A method and system for traffic signal response around a traffic accident

Abstract

The application relates to the technical field of traffic signal control, and provides a traffic accident surrounding traffic signal response method and system, which comprises the following steps: acquiring main road traffic flow parameters and secondary road exit vehicle existence information; judging whether the main road is in a main road congestion state; judging whether the secondary road is in a secondary road exit abnormal stagnation state; identifying a key exit passive obstruction event; sending a control instruction to a crossroad upstream of a target intersection corresponding to the key exit passive obstruction event, so that the crossroad upstream of the target intersection controls a main road direction signal lamp to be red to create a traffic gap; making the main road direction signal lamp of the target intersection turn to green to empty vehicles in a main road area in front of the key exit of the secondary road; after confirming that the emptying is completed, releasing the vehicles of the key exit; and after the releasing is completed, judging that an emergency condition is removed and traffic signal control is restored. The application has the advantages of avoiding traffic delay and potential public safety risks.

Description

Technical Field

[0001] This invention relates to the technical field of traffic signal control, and specifically to a method and system for responding to traffic signals around a traffic accident. Background Technology

[0002] Urban traffic management is facing increasingly complex challenges, especially when sudden traffic accidents cause localized traffic congestion. Traditional traffic signal control systems typically aim to improve the efficiency of main roads, but in certain scenarios, their inherent optimization strategies may lead to unexpected negative consequences.

[0003] For example, when a main road becomes congested due to an accident, and this congestion spreads upstream, physically blocking secondary road exits connecting to important emergency facilities, existing systems often struggle to accurately identify this special and high-risk situation. These systems may misjudge prolonged congestion of high-priority vehicles at secondary road exits as low traffic demand, thus continuing to prioritize traffic on the main road. This leads to severe delays in emergency response and could even trigger a public safety crisis. This combined effect of physical blockage and signal control logic misjudgment passively obstructs vehicles at critical exits, preventing them from timely access to the main road and severely hindering their mission, posing a potential threat to urban operations and public safety.

[0004] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this application provides a traffic signal response method and system for traffic accidents, which has the advantages of effectively identifying and responding to passive obstruction of key exits on secondary roads caused by traffic accidents, ensuring the timely passage of emergency vehicles or high-priority vehicles, and avoiding traffic delays and potential public safety risks.

[0006] This application provides a method for responding to traffic signals around a traffic accident, including:

[0007] Obtain traffic flow parameters of the main traffic arteries and vehicle presence information at the exits of secondary traffic arteries;

[0008] Based on the traffic flow parameters of the main road, determine whether the main road is in a state of congestion and obtain the main road status judgment result.

[0009] Based on the vehicle presence information at the secondary road exit, determine whether the secondary road is in an abnormal congestion state at the secondary road exit, and obtain the secondary road status judgment result;

[0010] When both the main road status assessment result and the secondary road status assessment result indicate "yes", identify and record it as a passive obstruction event of a critical exit.

[0011] After recording the passive obstruction event at a critical exit, an emergency response is initiated, and a control command is sent to the intersection upstream of the target intersection corresponding to the passive obstruction event, so that the traffic lights on the main road at the intersection upstream of the target intersection are set to red, thereby creating a traffic gap on the road section upstream of the target intersection.

[0012] After the traffic gap is created, turn the main road traffic light at the target intersection to green and clear the vehicles from the main road area in front of the key exit of the secondary road.

[0013] After confirming that the area of ​​the main road in front of the key exit of the secondary road has been cleared, vehicles at the key exit of the secondary road are allowed to pass.

[0014] Once vehicles have been allowed to pass through the key exits of the secondary road, the emergency situation is deemed over and traffic signal control is restored based on the preset initial signal.

[0015] The above-mentioned solution can effectively identify and respond to situations where critical exits on secondary roads are passively blocked due to traffic accidents, ensuring the timely passage of emergency vehicles or high-priority vehicles and avoiding traffic delays and potential public safety risks.

[0016] To further address the issue, this application also proposes the following steps: after recording a passive obstruction event at a critical exit, initiating an emergency response and sending a control command to the intersection upstream of the target intersection corresponding to the passive obstruction event, causing the traffic lights on the main road at the upstream intersection to turn red, thereby creating a traffic gap on the road segment upstream of the target intersection.

[0017] Send an emergency silence command to the intersection upstream of the target intersection corresponding to the passive obstruction of a critical exit;

[0018] The emergency silence command causes the signal control unit at the intersection upstream of the target intersection to enter an emergency silence state;

[0019] After entering emergency silence mode, the signal control unit stops responding to vehicle detector input signals related to the road segment upstream of the target intersection and locks the traffic lights leading to the target road segment to red, in order to create a traffic gap on the road segment upstream of the target intersection.

[0020] The above scheme further clarifies the specific emergency silence instructions and signal control logic for creating traffic gaps, improving the accuracy and efficiency of emergency response.

[0021] To improve the solution, this application also proposes steps for clearing vehicles from the area in front of the main road at the critical exit of the secondary road, including:

[0022] Turn the traffic light for the main road at the target intersection to green;

[0023] Obtain vehicle presence information in the area of ​​the main road ahead of the key exit of the secondary road;

[0024] Based on vehicle presence information, determine the clearance status of the main road area in front of the key exit of the secondary road;

[0025] When the clearance status has not met the preset clearance conditions, extend the green light duration of the main road direction traffic lights at the target intersection until the clearance status meets the preset clearance conditions.

[0026] After the preset clearing conditions are met, the system continuously acquires information on the presence of subsequent vehicles in the main road area ahead of the key exit of the secondary road.

[0027] When subsequent vehicle information indicates that a vehicle is re-entering the main road area ahead of the key exit of the secondary road, the green light duration of the main road direction signal light at the target intersection will be extended again.

[0028] The above scheme details the strategy for clearing vehicles from the main road area, ensuring thorough clearing by dynamically extending the green light duration, and addressing the situation of subsequent vehicles re-entering, thereby improving the effectiveness of the clearing operation.

[0029] To further address the issue, this application also proposes a step for determining the clearance status of the main road area ahead of a critical exit on a secondary road based on vehicle presence information, including:

[0030] Based on vehicle presence information, obtain the actual clearance space in the main road area ahead of the key exit of the secondary road;

[0031] Obtain the size information of vehicles waiting at key exits of secondary roads;

[0032] Based on the dimensional information, determine the minimum clearance space required for the main road area in front of the critical exit of the secondary road;

[0033] The actual cleared space is compared with the minimum required cleared space to determine the clearance status of the main road area in front of the critical exit of the secondary road.

[0034] The above scheme further refines the method for determining the emptying status. By comparing the actual emptying space with the minimum required emptying space, the emptying determination becomes more accurate and intelligent.

[0035] To improve the solution, this application also proposes that, after confirming that the area of ​​the main road ahead of the key exit of the secondary road has been cleared, the steps for allowing vehicles to pass through the key exit of the secondary road include:

[0036] After confirming that the main road area in front of the key exit of the secondary road has been cleared, obtain the traffic flow status information of the downstream section of the secondary road from the key exit.

[0037] Based on traffic flow information, determine the traffic capacity of the downstream sections of key exits of secondary roads;

[0038] If the traffic capacity is less than the preset traffic capacity threshold, vehicles at the key exits of the secondary road will be allowed to pass through with a delay.

[0039] If the traffic capacity is greater than or equal to the preset traffic capacity threshold, vehicles at the key exits of the secondary road are allowed to pass.

[0040] The above scheme adds the assessment of downstream road capacity before allowing vehicles on secondary roads to pass, avoiding immediate downstream congestion after vehicles on secondary roads are allowed to pass, and optimizing the overall traffic flow.

[0041] To further address the issue, this application also proposes steps to create traffic gaps on the road segment upstream of the target intersection, including:

[0042] Control the red light duration of the main road traffic lights at the intersection upstream of the target intersection;

[0043] Obtain the vehicle density of the road segment upstream of the target intersection;

[0044] Determine whether the vehicle density has reached the preset low-density state;

[0045] When the vehicle density does not reach the preset low density state, adjust the red light duration of the main road direction traffic lights at the intersection upstream of the target intersection until the vehicle density reaches the preset low density state, so as to create a traffic gap in the road section upstream of the target intersection.

[0046] The above scheme further refines the control strategy for creating traffic gaps. By dynamically adjusting the red light duration until the vehicle density reaches a preset low density state, the effective formation of traffic gaps is ensured.

[0047] To improve the solution, this application also proposes steps for obtaining the vehicle density of the road segment upstream of the target intersection, including:

[0048] Obtain vehicle presence information for the road segment upstream of the target intersection;

[0049] Identify non-moving vehicles and non-motorized vehicles in the vehicle presence information of the road segment upstream of the target intersection;

[0050] Excluding non-moving vehicles and non-motorized vehicles from the vehicle presence information of the road segment upstream of the target intersection, we obtain the vehicle presence information upstream of the target intersection;

[0051] Calculate the vehicle density of the road segment upstream of the target intersection based on the vehicle presence information upstream of the target intersection.

[0052] The above scheme clarifies the precise method for obtaining vehicle density. By excluding non-moving vehicles and non-motorized vehicles, the accuracy of vehicle density calculation is improved, thereby making the creation of traffic gaps more precise.

[0053] To further address the issue, this application also proposes that, after vehicles have cleared the critical exits of secondary roads, the steps for determining the emergency situation is over and restoring traffic signal control based on a preset initial signal include:

[0054] Obtain information on vehicle passage completion at key exits of secondary roads;

[0055] Based on the completion of passage information, the emergency situation is deemed to be lifted;

[0056] After the emergency is over, the signal control units at the target intersection and related intersections are switched from emergency mode to initial mode.

[0057] Load the preset timing scheme corresponding to the initial signal to restore traffic signal control.

[0058] The above scheme details the process of lifting the emergency and restoring traffic signals, ensuring that the system can smoothly switch back to normal mode from emergency mode and avoid secondary congestion.

[0059] To improve the solution, this application also proposes steps for obtaining traffic flow parameters of the main traffic artery and vehicle presence information at the exits of secondary traffic arteries, including:

[0060] Acquire raw traffic data from various types of traffic sensors within the area affected by a traffic accident;

[0061] Conduct a quality assessment of the raw traffic data;

[0062] Based on the quality assessment results, sensor data is filtered to obtain advanced sensor data;

[0063] The advanced sensor data is fused and verified to generate the final traffic data.

[0064] Based on the final traffic data, traffic flow parameters for the main traffic arteries and vehicle presence information at the exits of secondary traffic arteries are generated.

[0065] The above solution provides a detailed data processing workflow for obtaining traffic flow parameters and vehicle presence information, including data quality assessment, filtering, fusion, and verification, ensuring the accuracy and reliability of the input data.

[0066] To further address the problem, this application also proposes a traffic signal response system for the area surrounding a traffic accident, used to execute traffic signal responses around a traffic accident, comprising:

[0067] The parameter information acquisition module is used to acquire the main traffic flow parameters of the main traffic artery and the vehicle presence information at the exits of the secondary traffic arteries.

[0068] The main road status judgment module is used to determine whether the main road is in a congested state based on the main road traffic flow parameters, and obtain the main road status judgment result.

[0069] The secondary road status judgment module is used to determine whether the secondary road is in an abnormal congestion state at the secondary road exit based on the vehicle presence information at the secondary road exit, and to obtain the secondary road status judgment result.

[0070] The obstruction event identification module is used to identify and record a passive obstruction event at a critical exit when both the main road status judgment result and the secondary road status judgment result indicate yes.

[0071] The emergency response execution module is used to initiate an emergency response after recording a passive obstruction event at a critical exit. It sends a control command to the intersection upstream of the target intersection corresponding to the passive obstruction event, causing the traffic lights on the main road at the intersection upstream of the target intersection to turn red, thereby creating a traffic gap on the road section upstream of the target intersection.

[0072] The vehicle clearance execution module is used to turn the main road traffic light at the target intersection green after the traffic gap is created, clearing the vehicles in the main road area in front of the key exit of the secondary road.

[0073] The vehicle release execution module is used to release vehicles at the key exit of the secondary road after confirming that the area of ​​the main road in front of the key exit of the secondary road has been cleared.

[0074] The traffic signal restoration module is used to determine that the emergency situation has been resolved and restore traffic signal control based on the preset initial signal after vehicles have been allowed to pass through the key exits of the secondary road.

[0075] The above scheme provides a system for implementing the above method, enabling the method to be practically deployed and executed, and possessing good operability and practicality.

[0076] In summary, the traffic signal response method and system provided in this application for traffic accidents can effectively manage traffic and ensure priority passage for vehicles at key exits by intelligently identifying passive obstruction events at key exits and adopting a phased traffic signal control strategy. It has the advantages of effectively identifying and responding to passive obstruction of secondary road key exits caused by traffic accidents, ensuring the timely passage of emergency vehicles or high-priority vehicles, and avoiding traffic delays and potential public safety risks. Attached Figure Description

[0077] Figure 1 This is a flowchart of a traffic signal response method for a traffic accident perimeter according to one embodiment of the present invention;

[0078] Figure 2 This is one of the flowcharts of a traffic signal response method around a traffic accident according to another embodiment of the present invention;

[0079] Figure 3 This is a second flowchart of a traffic signal response method for traffic accidents in another embodiment of the present invention;

[0080] Figure 4 This is the third flowchart of a traffic signal response method for traffic accidents in another embodiment of the present invention;

[0081] Figure 5 This is the fourth flowchart of a traffic signal response method for traffic accidents in another embodiment of the present invention;

[0082] Figure 6 This is the fifth flowchart of a traffic signal response method for a traffic accident area according to another embodiment of the present invention;

[0083] Figure 7 This is a flowchart of a traffic signal response method for a traffic accident area according to another embodiment of the present invention;

[0084] Figure 8 This is the seventh flowchart of a traffic signal response method around a traffic accident according to another embodiment of the present invention;

[0085] Figure 9 This is the eighth flowchart of a traffic signal response method for traffic accidents in another embodiment of the present invention;

[0086] Figure 10 This is a system block diagram of a traffic signal response system around a traffic accident according to another embodiment of the present invention;

[0087] Explanation of reference numerals in the attached figures:

[0088] 1. Traffic signal response system around traffic accidents; 11. Parameter information acquisition module; 12. Main road status judgment module; 13. Secondary road status judgment module; 14. Obstruction event identification module; 15. Emergency response execution module; 16. Vehicle clearing execution module; 17. Vehicle release execution module; 18. Traffic signal restoration module. Detailed Implementation

[0089] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0090] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0091] Traditional traffic signal control systems, when dealing with traffic congestion on main roads caused by traffic accidents, are unable to effectively identify situations where the congestion on the main road physically blocks the exits of high-priority secondary roads. This results in the inability to take timely and targeted measures to lift the blockage, thereby affecting the traffic efficiency of secondary roads.

[0092] In response, this application proposes a traffic signal response method for areas surrounding traffic accidents, combining... Figure 1 As shown, it includes:

[0093] S1, obtain the main road traffic flow parameters of the main traffic artery and the vehicle presence information at the exit of the secondary road of the secondary traffic artery;

[0094] S2, based on the main road traffic flow parameters, determine whether the main road is in a congested state and obtain the main road status judgment result;

[0095] S3, based on the vehicle presence information at the secondary road exit, determine whether the secondary road is in an abnormal congestion state at the secondary road exit, and obtain the secondary road status judgment result;

[0096] S4. When both the main road status judgment result and the secondary road status judgment result indicate yes, identify and record it as a passive obstruction event of a critical exit.

[0097] S5, after recording the passive obstruction event of the key exit, initiates an emergency response and sends a control command to the intersection upstream of the target intersection corresponding to the passive obstruction event, so that the traffic lights of the main road direction at the intersection upstream of the target intersection are set to red, in order to create a traffic gap in the road section upstream of the target intersection.

[0098] S6, after the traffic gap is created, turns the main road traffic light at the target intersection to green, clearing vehicles from the main road area in front of the key exit of the secondary road.

[0099] S7, after confirming that the main road area in front of the key exit of the secondary road has been cleared, allows vehicles to pass through the key exit of the secondary road.

[0100] S8, after vehicles have been released from the key exits of the secondary road, determines that the emergency situation has been lifted and restores traffic signal control based on the preset initial signal.

[0101] Among them, the main road traffic flow parameters refer to the data set reflecting the traffic conditions of the main roads. These can be achieved using various traffic detection technologies, such as vehicle flow, speed, and occupancy detected by underground induction coils, or queue length and average speed obtained through video detector analysis. The main purpose is to obtain real-time traffic conditions of the main roads, providing a data basis for determining whether the main roads are congested. The secondary road exit vehicle presence information refers to signals or data indicating whether there are vehicles waiting to pass at the secondary road exits. This can be achieved using various sensor technologies, such as detecting vehicle crossing signals through ground induction coils, identifying vehicle presence through image recognition technology, or detecting vehicles through ultrasonic or radar sensors. The main purpose is to monitor whether there are vehicles lingering at the secondary road exits, providing a basis for determining whether there is abnormal congestion at the secondary road exits. Main road congestion refers to the traffic flow status exhibited when main road traffic flow parameters reach or exceed preset thresholds, such as vehicle speed below a specific value, vehicle density above a specific value, and queue length exceeding a specific length. Its primary purpose is to accurately identify whether traffic congestion has occurred on the main road, which is one of the prerequisites for triggering subsequent emergency responses. Secondary road exit abnormal congestion refers to the state where vehicles remain at secondary road exits for an extended period and are unable to leave normally. This can be determined based on vehicle presence information combined with time thresholds and vehicle movement status. For example, if vehicles remain at the exit for more than a preset time without significant movement, it is mainly to identify abnormal vehicle congestion at secondary road exits. This, along with main road congestion, constitutes the basis for judging passive obstruction events at critical exits. Passive obstruction events at critical exits refer to specific traffic events where secondary road exits are also in an abnormal congestion state while the main road is congested. This is mainly to accurately identify emergency situations where primary road congestion leads to the physical blockage of critical secondary road exits, thereby triggering targeted emergency responses. Traffic gaps refer to a section of the main road upstream of a target intersection that is free of vehicles or has extremely low vehicle density, created by signal control. This can be achieved by controlling the upstream traffic lights to be red, for example, by extending the red light duration to prevent vehicles from entering the section. The main purpose is to create enough space on the main road in front of the target intersection so that vehicles from secondary roads can safely and smoothly merge into the main road.

[0102] In some preferred embodiments, this application is implemented as follows. The system can acquire real-time traffic flow parameters of the main road, such as vehicle flow, average vehicle speed, lane occupancy, and queue length, through underground induction coil arrays and high-position video detectors deployed on the main traffic arteries. Simultaneously, at secondary road exits, independent induction coils or small millimeter-wave radar sensors can be installed to continuously detect whether vehicles are lingering in the exit area, thereby acquiring vehicle presence information at the secondary road exit. When determining the congestion status of the main road, the system can set a dynamic threshold; for example, when the average vehicle speed of a section of the main road is below 15 km / h for three consecutive signal cycles and the lane occupancy exceeds 80%, the main road is judged to be congested. For judging abnormal lingering at secondary road exits, the system can be set such that if the vehicle presence information at the secondary road exit shows a vehicle continuously present for more than 30 seconds, and the vehicle shows no significant displacement within the detection area, it is judged as abnormal lingering. When both conditions are met simultaneously, the system identifies and records it as a passive obstruction event at a critical exit. Once an incident is identified, the emergency response module immediately sends a command to the traffic signal control unit upstream of the target intersection. For example, this command could be a "mandatory red light" signal, causing the main road direction signal at the upstream intersection to immediately turn red and remain red for at least 60 seconds. This ensures a sufficient traffic gap is created in the section of road upstream of the target intersection to accommodate vehicles waiting to proceed from the secondary road. After the traffic gap is created, the main road direction signal at the target intersection turns green. The duration of this green light can be dynamically adjusted based on the vehicle clearance status of the main road area ahead of the secondary road exit. For example, through video analysis or inductive loop feedback, when the vehicle density in the area drops to a preset extremely low level (e.g., less than 5 vehicles / 100 meters), it is considered cleared. After confirming clearance, the system sends a green light command to the key exit signal lights of the secondary road, allowing waiting vehicles to proceed. Once clearance is complete, the system receives feedback that all vehicles on the secondary road have passed. At this point, the emergency situation is considered resolved, and the signal control units at the target intersection and related intersections are switched from emergency mode back to normal mode, loading the preset daily timing scheme and restoring normal traffic signal control.

[0103] Optional, combined Figure 2 As shown, after recording a passive obstruction event at a critical exit, S5 initiates an emergency response by sending a control command to the intersection upstream of the target intersection corresponding to the passive obstruction event. This command causes the traffic lights on the main road at the upstream intersection to turn red, creating a traffic gap on the road segment upstream of the target intersection. The steps include:

[0104] S51, send an emergency silence command to the intersection upstream of the target intersection corresponding to the passive obstruction event of a critical exit;

[0105] S52, the emergency silence command causes the signal control unit of the intersection upstream of the target intersection to enter the emergency silence state;

[0106] S53, after entering the emergency silence state, the signal control unit stops responding to vehicle detector input signals related to the road segment upstream of the target intersection and locks the traffic lights leading to the target road segment to the red state in order to create a traffic gap on the road segment upstream of the target intersection.

[0107] Emergency silence command refers to a special, high-priority control command designed to deviate the traffic signal control system from its regular signal timing logic and enter a preset emergency handling mode. This command can be sent via data packets, specifically coded signals, or dedicated communication protocols. A signal control unit (SCU) is a collection of hardware and software responsible for managing and controlling traffic lights, typically deployed at intersections or regional traffic control centers. It can be a standalone controller, an embedded system, or a node in a distributed control network. Emergency silence state refers to a non-standard operating mode entered by the SCU upon receiving an emergency silence command. In this mode, the SCU suspends or ignores regular traffic flow detection data input and enforces a preset emergency signal control strategy. Ceasing response to vehicle detector input signals related to the upstream road segment leading to the target intersection means that, in emergency silence state, the SCU stops processing or ignores real-time traffic data from vehicle detection equipment (such as inductive loop detectors, video detectors, and radar detectors) related to a specific road segment (i.e., the upstream road segment leading to the target intersection). This aims to prevent regular traffic demand assessments from interfering with emergency signal control. Locking the traffic lights leading to the target road segment to red means that the signal control unit, in emergency silence mode, forcibly sets the traffic lights controlling a specific direction (i.e., leading to the target road segment) to red, and does not change with regular signal timing or real-time traffic data changes. Its purpose is to ensure that vehicles in that direction stop passing, thereby providing conditions for creating traffic gaps.

[0108] In some preferred embodiments, this solution is implemented as follows: When the system detects a passive obstruction event at a critical exit, for example, through the main control server of the traffic management center, a predefined emergency silence command is sent to the intelligent traffic signal controller deployed at the intersection upstream of the target intersection. This command can be a TCP / IP data packet containing specific identifiers and control parameters, transmitted to the target controller via a fiber optic network or wireless communication module. Upon receiving the emergency silence command, the signal control unit inside the intelligent traffic signal controller, such as its main processor or dedicated control chip, immediately parses the command and switches its internal operating mode from the regular timing mode to the emergency silence state. After entering the emergency silence state, the signal control unit stops processing real-time input signals from vehicle detection devices such as inductive loop detectors, video detectors, or radar detectors related to the road segment upstream of the target intersection. This means that even if these detectors report the presence of vehicles or changes in traffic flow, the signal control unit will not adjust the traffic light status based on this information. At the same time, the signal control unit directly sends a command to the output module controlling the traffic lights leading to the target road segment, forcibly setting the traffic light in that direction to red and maintaining this red state until the emergency silence state is lifted. For example, by directly controlling a relay or solid-state switch, the red light can be kept on to prevent vehicles from entering the road segment, thus creating the necessary traffic gap on the road segment upstream of the target intersection.

[0109] Optional, combined Figure 3 As shown, the step of clearing vehicles from the main road area in front of the critical exit of the secondary road in step S6 includes:

[0110] S61, turns the main road traffic light at the target intersection to green;

[0111] S62, obtain vehicle presence information in the area of ​​the main road ahead of the key exit of the secondary road;

[0112] S63, based on vehicle presence information, determines the clearance status of the main road area in front of the key exit of the secondary road;

[0113] S64, when the clearance status has not met the preset clearance conditions, extend the green light duration of the main road direction traffic light at the target intersection until the clearance status meets the preset clearance conditions.

[0114] S65, after the preset clearing conditions are met in the clearing state, continuously acquires information on the presence of subsequent vehicles in the main road area ahead of the key exit of the secondary road;

[0115] S66: When subsequent vehicle information indicates that a vehicle is re-entering the main road area ahead of the key exit of the secondary road, the green light duration of the main road direction signal light at the target intersection will be extended again.

[0116] Vehicle presence information refers to real-time data collected by various traffic sensors (e.g., induction coils, video detectors, radar sensors) regarding the number, location, speed, and queue length of vehicles within a specific area. Its purpose is to provide a real-time snapshot of the traffic conditions in that area. Clearance status refers to a quantitative assessment of the vehicle situation in the area of ​​the main road preceding a key exit of a secondary road. This is used to determine whether the area has reached the conditions for vehicles from the secondary road to pass. Specifically, this can be determined by analyzing vehicle presence information, such as calculating the number of vehicles, vehicle density, or average vehicle speed in the area. Its purpose is to provide a basis for subsequent traffic light control decisions. Preset clearance conditions refer to pre-set thresholds or standards used to determine whether the area has reached a sufficient clearance level when clearing the area of ​​the main road preceding a key exit of a secondary road. Specifically, this can be set as the number of vehicles in the area being below a certain value, the vehicle density being below a certain threshold, the average vehicle speed being above a certain threshold, or even the absence of any vehicles in the area. Its purpose is to ensure that vehicles from the secondary road have sufficient space to safely enter the main road. Subsequent vehicle presence information refers to the real-time data on vehicle conditions in the main road area ahead of the key exit of the secondary road that is cleared according to the preset conditions. Its purpose is to monitor whether new vehicles re-enter the cleared area to prevent the clearing effect from being compromised.

[0117] In some preferred embodiments, clearing vehicles from the main road area ahead of a critical exit on a secondary road can be implemented as follows: First, once the traffic gap is created, the main road directional traffic light at the target intersection is turned green by the control unit, allowing vehicles on the main road to pass. Then, multiple high-precision video detectors and induction coils deployed in the main road area ahead of the critical exit can acquire real-time vehicle presence information in the area. This information includes, but is not limited to, the number of vehicles in the area, the average speed of vehicles, and the queue length. Next, a processing module in a central traffic management system determines the clearance status of the main road area ahead of the critical exit on the secondary road based on this vehicle presence information. For example, the processing module can calculate the vehicle density in the area or assess the available space in the area. When it is determined that the clearance status has not met the preset clearance conditions (e.g., the vehicle density in the area is still higher than 10 vehicles per kilometer, or the available space is insufficient to accommodate an emergency vehicle), the processing module sends a command to the signal control unit at the target intersection to extend the green light duration of the main road directional traffic light. This extension process continues, for example, by 5 seconds each time, until the vehicle density in the area drops below 5 vehicles per kilometer, or the available space reaches the preset standard. Once the preset clearance conditions are met, the video detectors and induction coils continuously send subsequent vehicle presence information to the central traffic management system to monitor the traffic conditions in the area in real time. If the subsequent vehicle presence information indicates that vehicles are re-entering the main road area ahead of the secondary road's key exit (e.g., the vehicle density rises again to more than 8 vehicles per kilometer), the processing module will immediately send an instruction to the signal control unit again to extend the green light duration of the main road's direction signal light to ensure that the area remains clear before vehicles on the secondary road are allowed to pass.

[0118] Optional, combined Figure 4 As shown, the steps by which S63 determines the clearance status of the main road area ahead of the critical exit of the secondary road based on vehicle presence information include:

[0119] S631, based on vehicle presence information, obtain the actual clear space in the main road area ahead of the key exit of the secondary road;

[0120] S632, Obtain the size information of vehicles waiting at the critical exit of the secondary road;

[0121] S633, based on dimensional information, determine the minimum clearance space required for the main road area in front of the critical exit of the secondary road;

[0122] S634 compares the actual cleared space with the minimum required cleared space to determine the cleared status of the main road area in front of the critical exit of the secondary road.

[0123] The actual clear space refers to the size of the unobstructed space currently available for vehicle passage within the main road area in front of the critical exit of the secondary road. This can be obtained by analyzing vehicle position, spacing, and movement trajectories using sensor data such as visual recognition, radar detection, or laser scanning to calculate the continuous, usable clearance length or area in real time. Its purpose is to quantify the actual available space on the main road for vehicles merging from the secondary road. Size information refers to the physical dimensions of vehicles waiting to merge onto the main road at the critical exit of the secondary road, such as vehicle length, width, or vehicle type. This can be obtained by classifying and estimating vehicle dimensions using image recognition technology, or by matching vehicle detectors with a pre-set vehicle type database. Its purpose is to accurately assess the minimum space requirements for waiting vehicles to merge onto the main road. The minimum required clear space refers to the minimum unobstructed space that must be available in the area in front of the main road to ensure that vehicles waiting at the critical exit of the secondary road can safely and smoothly merge onto the main road. It can be determined by using the size information of waiting vehicles, combined with preset safety margins, turning radii, or merging path models, through methods such as table lookup, formula calculation, or dynamic programming. Its purpose is to provide an objective and dynamic standard for determining the clearance status, ensuring safe merging. Clearance status refers to whether the area of ​​the main road ahead of the critical exit of the secondary road has reached a level sufficient to safely allow vehicles from the secondary road to pass. This can be determined by logically comparing the actual clearance space with the minimum required clearance space, for example, by determining whether the actual clearance space is greater than or equal to the minimum required clearance space. Its purpose is to provide a clear decision-making basis for determining whether vehicles from the secondary road can be allowed to pass.

[0124] In some preferred embodiments, determining the clearance status of the main road area ahead of the critical exit of the secondary road can be implemented as follows. First, to obtain the actual clearance space of the main road area ahead of the critical exit of the secondary road, video detectors or millimeter-wave radar installed above the main road can be used. These sensors continuously monitor the distribution and movement of vehicles in the area, and through image processing algorithms or radar signal analysis, identify the gaps between vehicles and calculate the length or area of ​​these gaps, thereby obtaining the actual clearance space. For example, if a continuous area without vehicles exceeding a preset threshold is detected, it is considered that there is usable clearance space. Simultaneously, to obtain the size information of waiting vehicles at the critical exit of the secondary road, roadside laser scanners or high-precision cameras can be used, combined with vehicle recognition algorithms, to classify the waiting vehicles by type and estimate their approximate size. This size information may include the length and width of the vehicles. Then, based on the obtained size information of the waiting vehicles, the system can consult a preset size-space requirement lookup table or use a dynamic calculation model to determine the minimum clearance space required for the main road area ahead of the critical exit of the secondary road. For example, the minimum clearance space required for a truck waiting to merge is larger than that for a car, taking into account its turning radius and safety distance. Finally, the actual clearance space calculated in real time is compared with the minimum clearance space required based on the size of the waiting vehicles. If the actual clearance space is greater than or equal to the minimum clearance space required, the area is considered cleared, and vehicles on the secondary road can safely proceed; otherwise, it is considered not cleared, and the green light duration on the main road needs to be extended to create sufficient clearance space.

[0125] Optional, combined Figure 5 As shown, after confirming that the main road area in front of the key exit of the secondary road has been cleared, S7's steps for releasing vehicles to the key exit of the secondary road include:

[0126] S71: After confirming that the main road area in front of the key exit of the secondary road has been cleared, obtain the traffic flow status information of the downstream section of the key exit of the secondary road.

[0127] S72, based on traffic flow status information, determines the traffic capacity of the downstream section of the key exit of the secondary road;

[0128] S73, if the traffic capacity is less than the preset traffic capacity threshold, then delay the release of vehicles at the key exits of the secondary road;

[0129] S74 If the traffic capacity is greater than or equal to the preset traffic capacity threshold, vehicles at the key exits of the secondary road are allowed to pass.

[0130] Traffic flow status information refers to a set of data reflecting the current traffic conditions of a specific road segment, which can be characterized by parameters such as vehicle speed, vehicle density, lane occupancy, queue length, and travel time. Capacity refers to the maximum number of vehicles that can safely and smoothly pass through a specific road segment within a given time. It can be calculated based on traffic flow status information, for example, by analyzing the relationship between vehicle density and speed. Capacity thresholds are preset reference values ​​used to determine whether a road segment has sufficient traffic space. Their purpose is to provide a basis for decision-making regarding whether to allow vehicles on secondary roads to pass, and they can be set based on road design standards, historical traffic data, or real-time traffic management strategies.

[0131] In some preferred embodiments, this application is implemented as follows: After confirming that the area of ​​the main road ahead of the key exit of the secondary road has been cleared, the traffic management system can obtain traffic flow status information of the downstream section of the secondary road through various sensors. For example, loop detectors, video detectors, or radar sensors installed on the downstream section can be used to collect data such as vehicle flow, speed, and occupancy in real time. This raw data is transmitted to the central processing unit, which performs data fusion and analysis to generate accurate traffic flow status information.

[0132] Specifically, the central processing unit can calculate the vehicle density of downstream road segments based on collected traffic flow and road length data. Simultaneously, by combining this with the average vehicle speed, it can further assess the traffic capacity of the road segment. For example, when the vehicle density exceeds 30 vehicles per kilometer and the average speed is below 20 km / h, a preliminary assessment of low traffic capacity can be made. The system will compare the calculated traffic capacity with a preset traffic capacity threshold. This threshold can be dynamically adjusted based on road grade, design speed, and historical traffic data. For example, for urban arterial roads, the traffic capacity threshold can be set at 1500 vehicles per lane per hour.

[0133] If the calculated capacity is below this threshold, for example, only 800 vehicles per lane per hour, the system will issue a delayed release instruction, keeping the traffic lights at key exits of the secondary road red, or extending the duration of their red status. The system will continuously monitor the traffic flow status of downstream road segments until the capacity recovers to or exceeds the preset threshold. Once the capacity reaches or exceeds the threshold, for example, recovering to 1600 vehicles per lane per hour, the system will immediately issue a release instruction, turning the traffic lights at key exits of the secondary road green, allowing waiting vehicles to safely merge into the main road. This dynamic decision-making mechanism based on the capacity of downstream road segments ensures that the release of vehicles from secondary roads is carried out under the premise that the overall traffic flow on the main road is controllable and safe.

[0134] Optional, combined Figure 6As shown, the step of creating a traffic gap on the road segment upstream of the target intersection in step S53 includes:

[0135] S531 controls the red light duration of the main road traffic lights at the intersection upstream of the target intersection.

[0136] S532, obtain the vehicle density of the road segment upstream of the target intersection;

[0137] S533, determine whether the vehicle density has reached the preset low density state;

[0138] S534 When the vehicle density does not reach the preset low density state, adjust the red light duration of the main road direction traffic lights at the intersection upstream of the target intersection until the vehicle density reaches the preset low density state, so as to create a traffic gap in the road section upstream of the target intersection.

[0139] Vehicle density refers to the number of vehicles per unit length on a specific road segment. It can be calculated using vehicle presence information obtained through induction coils, video detectors, radar sensors, or floating car data. The preset low-density state refers to a pre-defined threshold state indicating sparse traffic flow or a low number of vehicles on a road segment. Specifically, it can be a vehicle density value, such as the number of vehicles per kilometer being below a certain value, or a state determined based on comprehensive indicators such as traffic capacity and queue length. Its purpose is to ensure sufficient space on the target road segment so that vehicles from secondary roads can smoothly merge into the main road.

[0140] In some preferred embodiments, when the system detects a passive obstruction event at a critical exit and initiates an emergency response, the signal control unit at the intersection upstream of the target intersection receives an emergency silence command and enters an emergency silence state. At this time, the signal control unit first sets the traffic lights for the main road direction to red and sets an initial red light duration, such as 30 seconds. Simultaneously, multiple traffic sensors deployed on the road segment upstream of the target intersection, such as induction coil arrays or high-definition video detectors, continuously collect real-time traffic data for that segment, including information such as the number of vehicles passing through, occupancy rate, and queue length. This raw data is transmitted to a traffic data processing module, which calculates the current vehicle density based on a preset algorithm, such as dividing the number of vehicles by the segment length. Subsequently, the traffic data processing module compares the calculated vehicle density with a preset low-density threshold, for example, a vehicle density below 10 vehicles per kilometer. If the currently calculated vehicle density is higher than this threshold, the traffic data processing module sends a command to the signal control unit, instructing it to extend the red light duration for the main road direction traffic lights, for example, by 5 seconds each time. Upon receiving the instruction, the signal control unit immediately updates the red light duration and maintains the red light status. This process is repeated cyclically. The traffic data processing module continuously acquires updated vehicle density and dynamically adjusts the red light duration based on comparisons with preset low-density conditions until the vehicle density of the target road segment reaches or falls below the preset low-density state. Once the low-density state is reached, the system considers the traffic gap to have been created, thus preparing for subsequent emergency passage.

[0141] Optional, combined Figure 7 As shown, the steps in S532 for obtaining the vehicle density of the road segment upstream of the target intersection include:

[0142] A1, obtain vehicle presence information for the road segment upstream of the target intersection;

[0143] A2, identify non-moving vehicles and non-motorized vehicles in the vehicle presence information of the road segment upstream of the target intersection;

[0144] A3, exclude non-moving vehicles and non-motorized vehicles from the vehicle presence information of the road segment upstream of the target intersection, and obtain the vehicle presence information upstream of the target intersection;

[0145] A4. Calculate the vehicle density of the road segment upstream of the target intersection based on the vehicle presence information upstream of the target intersection.

[0146] Vehicle presence information refers to a set of data describing the location, quantity, or status of vehicles on a specific road segment. This data can be obtained through various means, including video images, radar signals, geomagnetic induction data, or lidar point cloud data. Non-moving vehicles are those whose position or speed changes do not reach a preset threshold within a specific time period. This can be determined by analyzing continuous position or speed data, aiming to distinguish between vehicles that are moving normally or briefly stopping, and those that are parked for extended periods or have malfunctions. Non-motorized vehicles are those that are not driven by an engine or motor but primarily by human or animal power, such as bicycles, electric bicycles, or tricycles. They can be identified by their size, shape, or movement patterns, with the aim of excluding non-motorized vehicles from motorized vehicle statistics to obtain accurate motorized traffic flow data.

[0147] In some preferred embodiments, obtaining vehicle presence information on the road segment upstream of the target intersection can be achieved specifically through video surveillance cameras and millimeter-wave radar deployed above the road segment. The video surveillance cameras can continuously capture real-time images or video data of the road segment, while the millimeter-wave radar can provide vehicle speed, distance, and angle information. Identifying non-moving vehicles and non-motorized vehicles in the vehicle presence information of the road segment upstream of the target intersection can utilize image processing techniques and machine learning models. For example, for video data, object detection algorithms (such as YOLO and Faster R-CNN) can be used to identify the vehicle type (motorized vehicle, bicycle, electric vehicle) and its position in the image. Simultaneously, by analyzing vehicle position changes between consecutive frames, combined with millimeter-wave radar speed data, it can be determined whether a vehicle is in a non-moving state. For example, if a vehicle's position change is less than a preset threshold within several seconds, or its speed remains close to zero, it can be identified as a non-moving vehicle. For non-motorized vehicles, in addition to type identification, their typical motion patterns and speed ranges can be used for auxiliary judgment. Excluding non-moving vehicles and non-motorized vehicles from the vehicle presence information of the road segment upstream of the target intersection, the vehicle presence information upstream of the target intersection is obtained. This can be achieved by marking the identified non-moving vehicles and non-motorized vehicles as invalid or removing them directly from the statistical data set in the data processing unit. For example, in the vehicle list, the identifiers of these vehicles can be removed from the valid vehicle count, or in image analysis, only the areas identified as motorized vehicles can be further processed. Based on the vehicle presence information upstream of the target intersection, the vehicle density of the road segment upstream of the target intersection can be calculated. This can be done by counting the number of motorized vehicles on the target road segment within a specific time window and dividing that number by the length of the road segment. For example, if the road segment length is L and the number of motorized vehicles is N, the vehicle density can be calculated as N / L. This calculation result will serve as the basis for determining whether the road segment has reached a preset low-density state, thereby guiding the adjustment of traffic lights.

[0148] Optional, combined Figure 8 As shown, after S8 has released vehicles from the key exits of the secondary road, the steps for determining that the emergency situation has been resolved and restoring traffic signal control based on the preset initial signal include:

[0149] S81, obtain information on the completion of vehicle passage at key exits of secondary roads;

[0150] S82, based on the information indicating completion of passage, determines that the emergency situation has been lifted;

[0151] S83, after the emergency situation is over, switches the signal control units of the target intersection and related intersections from emergency mode to initial mode;

[0152] S84, load the preset timing scheme corresponding to the initial signal to restore traffic signal control.

[0153] Among them, "passage completion information" refers to data indicating whether vehicles have completely passed through or left the exit area at a key exit of a secondary road. This data can be obtained using real-time monitoring data such as the number of vehicles, speed, position, or queue length from vehicle detectors (e.g., geomagnetic sensors, video detectors, or radar sensors). "Emergency situation cleared" refers to the system's determination that vehicles at the key exit of the secondary road have safely passed through and no further special emergency traffic signal control is needed. This can be determined logically based on the passage completion information, such as when the vehicle density in the exit area is below a preset threshold or there are no vehicles remaining. "Emergency mode" refers to a mode that the traffic signal control unit enters when a passive obstruction event occurs at a key exit. Special operating states can manifest as temporary adjustments to signal timing schemes to prioritize the passage of vehicles on secondary roads, or the creation of traffic gaps on main roads. The initial mode refers to a normal operating state that the traffic signal control unit returns to after the emergency situation is resolved. This can manifest as control according to a preset normal signal timing scheme or a timing scheme that is adaptively adjusted based on real-time traffic flow. The preset timing scheme corresponding to the initial signal refers to a set of parameters such as cycle, phase, and green ratio that are pre-configured for a specific intersection or area under normal traffic system conditions to guide traffic light switching. These parameters can be formulated and stored based on historical traffic data, road network structure, or traffic management strategies.

[0154] In some preferred embodiments, this application is implemented as follows. After vehicles have completed exiting the key exit of the secondary road, the traffic signal control system acquires real-time vehicle passage completion information in the area through video detectors or geomagnetic sensors deployed at the key exit of the secondary road. For example, the video detector can continuously analyze image frames in the exit area, identify and track vehicle movement trajectories, and generate a passage completion signal when it detects that all waiting vehicles have left the exit area and no new vehicles have entered the area within a certain time (e.g., 5 seconds). Based on this passage completion information, the system determines that the emergency situation has been lifted. Specifically, when a passage completion signal is received and it is confirmed that the vehicle density in the key exit area has dropped below a preset zero density threshold, the system triggers the determination that the emergency situation has been lifted. After the emergency situation is lifted, the traffic signal control system sends instructions to the signal control units of the target intersection and the upstream and downstream intersections related to this emergency response, causing these signal control units to switch from emergency mode to initial mode. For example, a mode switching command packet can be sent to each signal control unit via wired or wireless network communication protocols. This command packet instructs the control unit to stop executing the current emergency timing logic and prepare to load the regular timing scheme. Subsequently, these signal control units load the preset timing scheme corresponding to the initial signal from their internal memory or the central control server. For example, each signal control unit has multiple pre-stored regular timing schemes based on different time periods or traffic flow characteristics. The system will select and load the most suitable timing scheme according to the current time period (e.g., off-peak period) or real-time traffic flow data. For example, loading a regular timing scheme with a cycle of 120 seconds, a green light duration of 70 seconds for main roads, and a green light duration of 30 seconds for secondary roads, thereby restoring traffic signal control and returning the intersection traffic flow to normal management.

[0155] Optional, combined Figure 9 As shown, the steps in S1 for obtaining the main road traffic flow parameters and the secondary road exit vehicle presence information of the secondary roads include:

[0156] S11, acquire raw traffic data from various types of traffic sensors within the traffic accident area;

[0157] S12, conduct quality assessment of raw traffic data;

[0158] S13. Based on the results of the quality assessment, filter the sensor data to obtain advanced sensor data;

[0159] S14, fuse and verify advanced sensor data to generate final traffic data;

[0160] S15, based on the final traffic data, generates the main road traffic flow parameters of the main traffic artery and the vehicle presence information at the exits of the secondary traffic arteries.

[0161] Traffic sensors of various types refer to different kinds of devices used to collect traffic information, such as geomagnetic sensors, radar sensors, video detectors, ultrasonic sensors, or floating car data acquisition devices, etc., with the aim of providing multi-source heterogeneous traffic data. Raw traffic data refers to the initial data directly acquired from the aforementioned traffic sensors without any processing or preliminary processing, such as vehicle counts, speeds, occupancy rates, queue lengths, vehicle images, or GPS trajectories, etc., with the aim of serving as the basis for subsequent data processing. Quality assessment refers to the process of checking and judging the completeness, accuracy, consistency, and timeliness of raw traffic data. Specifically, this may include missing value detection, outlier identification, data format verification, or timestamp synchronization checks, with the aim of identifying and marking low-quality or unreliable data. Sensor data screening refers to selecting a subset of data from the raw traffic data that meets preset quality standards based on the results of the quality assessment. Specifically, this may involve setting thresholds to remove data marked as abnormal or incomplete, with the aim of ensuring high reliability of the data for subsequent processing. Advanced sensor data refers to sensor data that, after quality assessment and screening, meets certain quality requirements and can be used for further processing, with the aim of providing clean data input for data fusion and verification. Fusion and verification refers to the process of integrating data from different sensors or different types of data, and then checking and correcting the consistency of the integrated data. Specifically, data fusion can be performed using weighted averaging, Kalman filtering, Bayesian networks, or multi-sensor data association algorithms, and data verification can be performed through cross-validation, logical consistency checks, or comparison with historical data. The purpose is to eliminate data redundancy, make up for missing data, and correct data biases, thereby generating more comprehensive, accurate, and robust traffic data.

[0162] In some preferred embodiments, acquiring raw traffic data from various types of traffic sensors within the accident area can specifically involve: real-time collection of vehicle flow, speed, occupancy, queue length, vehicle image sequences, and vehicle location information via loop detectors, video surveillance cameras, radar sensors, and accessed floating car GPS data deployed in and around the accident area. Quality assessment of the raw traffic data can specifically involve: imputing missing values ​​in loop data, for example, interpolating using data from adjacent time periods or adjacent loops; evaluating image clarity and detecting abnormal frames in video data; performing signal-to-noise ratio analysis on radar data; and synchronously verifying the timestamps of all data to identify and mark abnormal values ​​such as missing data packets, sensor malfunctions, or significant deviations from the normal range. Based on the quality assessment results, filtering sensor data to obtain advanced sensor data can specifically involve: removing data sources marked as low quality or abnormal; for example, if a loop continuously reports zero flow or abnormally high flow for more than a preset time, temporarily disabling the data from that loop; and not using video analysis results for periods of video that are blurry. The fusion and verification of advanced sensor data can be specifically performed as follows: Similar data from different sensors, such as traffic flow data detected by both loop detectors and video feeds, are weighted and averaged. The weights can be dynamically adjusted based on the historical reliability or real-time confidence level of the sensors. Simultaneously, vehicle speed data is smoothed using a Kalman filter algorithm and logically verified. For example, it checks whether the relationship between vehicle flow and occupancy conforms to basic traffic flow theory; if not, corrections are made. Based on the final traffic data, generating mainline traffic flow parameters for the main road and vehicle presence information for secondary road exits can be specifically performed as follows: Based on the fused and verified data, the real-time flow, average speed, and vehicle density of each lane on the main road are calculated as mainline traffic flow parameters. Simultaneously, by analyzing vehicle identification results in video images or continuous occupancy signals from loop detectors at secondary road exits, it is determined whether vehicles are lingering at the exit for extended periods, thus generating vehicle presence information for secondary road exits.

[0163] A traffic signal response system for the vicinity of a traffic accident, used to execute traffic signal responses around a traffic accident, combined with... Figure 10 As shown, the traffic signal response system 1 around a traffic accident includes:

[0164] The parameter information acquisition module 11 is used to acquire the main road traffic flow parameters of the main traffic artery and the vehicle presence information at the exit of the secondary road of the secondary traffic artery.

[0165] The main road status judgment module 12 is used to determine whether the main road is in a congested state based on the main road traffic flow parameters, and to obtain the main road status judgment result.

[0166] The secondary road status judgment module 13 is used to determine whether the secondary road is in an abnormal congestion state at the secondary road exit based on the vehicle presence information at the secondary road exit, and to obtain the secondary road status judgment result.

[0167] The obstruction event identification module 14 is used to identify and record a passive obstruction event at a critical exit when both the main road status judgment result and the secondary road status judgment result indicate yes.

[0168] The emergency response execution module 15 is used to activate the emergency response after recording the passive obstruction event of the key exit, and send a control command to the intersection upstream of the target intersection corresponding to the passive obstruction event, so that the traffic lights of the main road direction at the intersection upstream of the target intersection are set to red, so as to create a traffic gap in the road section upstream of the target intersection.

[0169] The vehicle clearing execution module 16 is used to turn the main road direction traffic light of the target intersection to green after the traffic gap is created, and clear the vehicles in the main road area in front of the key exit of the secondary road.

[0170] The vehicle release execution module 17 is used to release vehicles at the key exit of the secondary road after confirming that the main road area in front of the key exit of the secondary road has been cleared.

[0171] The traffic signal restoration module 18 is used to determine that the emergency situation has been lifted and restore traffic signal control based on the preset initial signal after vehicles have been released from the key exits of the secondary road.

[0172] The parameter information acquisition module is a unit used to collect and process traffic data. It can be implemented by connecting to various traffic sensors (e.g., inductive loops, video detectors, radar sensors, or floating car data interfaces), aiming to provide basic data for subsequent traffic condition assessment and emergency response. The main road condition assessment module is a logical unit used to analyze main road traffic flow parameters to identify congestion. It can be implemented by real-time calculation and threshold comparison based on indicators such as traffic flow density, speed, occupancy, or queue length. Its purpose is to identify congestion on main roads and provide a basis for determining whether key exits are passively blocked. The secondary road condition assessment module is a logical unit used to analyze vehicle presence information at secondary road exits to identify abnormal congestion. It can be implemented by continuously monitoring indicators such as vehicle dwell time, number of vehicles, or queue length in the exit area and comparing them with preset abnormal congestion thresholds. Its purpose is to identify abnormal congestion at secondary road exits and combine this with the main road condition assessment results to determine whether a key exit has been passively blocked. The obstruction event identification module is a decision-making unit used to comprehensively judge the status of the main road and secondary roads to identify passive obstruction events at key exits. It can receive and logically judge the judgment results from the main road status judgment module and the secondary road status judgment module, triggering event recording when both meet specific conditions. Its purpose is to identify key traffic obstruction events requiring special intervention as trigger conditions for initiating emergency response. The emergency response execution module is a control unit used to activate and coordinate traffic signal control to create traffic gaps after identifying passive obstruction events at key exits. It can send signal control commands to the intersection upstream of the target intersection, turning the traffic lights on the main road red, thereby creating vehicle gaps in a specific road section. Its purpose is to create passage space for vehicles entering from secondary roads, avoiding passively waiting for the main road to naturally disperse. The vehicle clearance execution module is a control unit used to clear vehicles from the main road area in front of the key exit of the secondary road after a traffic gap has formed, through signal control. This can be achieved by turning the main road direction traffic light at the target intersection green and adjusting the green light duration according to the actual clearance situation. Its purpose is to remove obstacles in front of the key exit, providing physical convenience for the passage of vehicles on the secondary road. The vehicle release execution module is a control unit used to release vehicles from the key exit of the secondary road after confirming that the main road area has been cleared. This can be achieved by sending a passage command to the key exit of the secondary road after confirming that the clearance conditions have been met. Its purpose is to ensure that vehicles on the secondary road can safely and with sufficient space enter the main road, avoiding prolonged congestion.The traffic signal restoration module is a control unit used to restore traffic signal control to normal or preset state after the emergency situation is handled. It can be implemented by determining that the emergency situation has been lifted and loading the preset initial signal timing scheme after the secondary road vehicles have been released. Its purpose is to avoid the emergency response causing unnecessary long-term impact on other traffic flows and to ensure the overall operation of the traffic system.

[0173] In some preferred embodiments, this application is implemented as follows. A traffic signal response system around a traffic accident can be deployed in the urban traffic management center as a subsystem of the intelligent traffic management platform. The parameter information acquisition module can be a data acquisition and preprocessing unit, which receives raw traffic data transmitted in real time from inductive loop detectors at intersections, video surveillance cameras, microwave radar, and floating car data platforms via wired or wireless network interfaces. This module performs preliminary cleaning, format conversion, and timestamping on the received data to ensure data availability and consistency. The main road status judgment module and the secondary road status judgment module can run as independent software services on the system's central processing server. The main road status judgment module can output the main road congestion status based on the traffic flow, average speed, and lane occupancy data provided by the parameter information acquisition module, using a preset congestion judgment algorithm (e.g., when the speed is below a certain threshold and the lane occupancy is above a certain threshold, it is judged as congestion). The secondary road status judgment module can determine whether the secondary road is in an abnormal congestion state based on vehicle presence signals in the secondary road exit area (e.g., continuous triggering signals from inductive loops or video analysis identifying vehicles stationary for extended periods) and vehicle queue length information. The obstruction event recognition module can be an event trigger that continuously monitors the outputs of the main road status judgment module and the secondary road status judgment module. When both modules simultaneously issue "congestion" and "abnormal congestion" signals, this module immediately identifies and records it as a "passive obstruction event at a critical exit" and sends this event information to the emergency response execution module. The emergency response execution module can be a signal control command generation and transmission unit. Upon receiving the obstruction event information, it immediately generates signal control commands for the upstream intersection of the target intersection. For example, this command could instruct the signal controller at the upstream intersection to immediately switch the main road traffic light to red and maintain it for a period of time to create a vehicle-free area, i.e., a traffic gap, on the main road. The vehicle clearing execution module can be a dynamic signal adjustment unit. After the traffic gap is created, it sends a command to the target intersection to turn the main road traffic light green. Simultaneously, this module continuously monitors vehicle presence in the main road area preceding the secondary road's key exit. If vehicles remain in this area, the green light duration can be extended until the area is cleared. The vehicle release execution module can be a passage permission granting unit. After confirming that the main road area preceding the secondary road's key exit has been cleared, it sends a command to the target intersection, causing the traffic light at the secondary road's key exit to turn green, allowing vehicles from the secondary road to enter the main road. The traffic signal restoration module can be a mode switching and timing loading unit. After the secondary road's vehicle release is complete, it receives a passage completion signal and determines that the emergency situation has been resolved.Subsequently, the module sends instructions to the signal controllers of the target intersection and related intersections, causing them to switch from emergency mode back to initial mode and load the preset initial signal timing scheme, thereby restoring normal traffic signal control.

[0174] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for responding to traffic signals around a traffic accident, characterized in that, include: Obtain traffic flow parameters of the main traffic arteries and vehicle presence information at the exits of secondary traffic arteries; Based on the main road traffic flow parameters, determine whether the main road is in a congested state and obtain the main road status judgment result. Based on the vehicle presence information at the secondary road exit, determine whether the secondary road is in an abnormal congestion state at the secondary road exit, and obtain the secondary road status judgment result. When both the main road status assessment result and the secondary road status assessment result indicate "yes", identify and record it as a passive obstruction event of a critical exit. After recording the passive obstruction event of a key exit, an emergency response is initiated, and a control command is sent to the intersection upstream of the target intersection corresponding to the passive obstruction event of the key exit, so that the traffic lights of the main road direction at the intersection upstream of the target intersection are set to red, in order to create a traffic gap in the road section upstream of the target intersection. After the traffic gap is created, the main road traffic light at the target intersection is turned green, clearing the vehicles from the main road area in front of the key exit of the secondary road. The steps for clearing vehicles from the main road area ahead of the critical exit of the secondary road include: Turn the traffic light for the main road at the target intersection to green; Obtain vehicle presence information in the area of ​​the main road ahead of the key exit of the secondary road; Based on the vehicle presence information, determine the clearance status of the main road area in front of the key exit of the secondary road; When the clearing state does not meet the preset clearing conditions, the green light duration of the main road direction traffic light at the target intersection is extended until the clearing state meets the preset clearing conditions. After the clearing state reaches the preset clearing conditions, the system continuously acquires information on the presence of subsequent vehicles in the main road area ahead of the key exit of the secondary road. When subsequent vehicle information indicates that a vehicle is re-entering the main road area ahead of the key exit of the secondary road, the green light duration of the main road direction signal light at the target intersection will be extended again. After confirming that the area of ​​the main road in front of the key exit of the secondary road has been cleared, vehicles at the key exit of the secondary road are allowed to pass. Once vehicles have been allowed to pass through the key exits of the secondary road, the emergency situation is deemed over and traffic signal control is restored based on the preset initial signal.

2. The traffic signal response method around a traffic accident according to claim 1, characterized in that, The step of initiating an emergency response after recording a passive obstruction event at a key exit, and sending a control command to the intersection upstream of the target intersection corresponding to the passive obstruction event, to set the main road traffic lights at the upstream intersection to red, thereby creating a traffic gap on the road segment upstream of the target intersection, includes: Send an emergency silence command to the intersection upstream of the target intersection corresponding to the passive obstruction event of the critical exit; The emergency silence command causes the signal control unit at the intersection upstream of the target intersection to enter an emergency silence state. After entering the emergency silence state, the signal control unit stops responding to vehicle detector input signals related to the road segment upstream of the target intersection and locks the traffic lights leading to the target road segment to a red state in order to create a traffic gap on the road segment upstream of the target intersection.

3. The traffic signal response method around a traffic accident according to claim 1, characterized in that, The step of determining the clearance status of the main road area ahead of the critical exit of the secondary road based on the vehicle presence information includes: Based on the vehicle presence information, the actual clear space in the main road area ahead of the key exit of the secondary road is obtained; Obtain the size information of vehicles waiting at key exits of secondary roads; Based on the aforementioned dimensional information, determine the minimum required clearance space for the main road area in front of the critical exit of the secondary road; The actual cleared space is compared with the minimum required cleared space to determine the clearing status of the main road area in front of the key exit of the secondary road.

4. The traffic signal response method around a traffic accident according to claim 1, characterized in that, The steps for releasing vehicles exiting the secondary road at the key exit after confirming that the area on the main road ahead of the key exit of the secondary road has been cleared include: After confirming that the main road area in front of the key exit of the secondary road has been cleared, obtain the traffic flow status information of the downstream section of the secondary road from the key exit. Based on the traffic flow status information, determine the traffic capacity of the downstream section of the key exit of the secondary road; If the traffic capacity is less than a preset traffic capacity threshold, vehicles at the key exits of the secondary road will be allowed to pass through with a delay. If the traffic capacity is greater than or equal to a preset traffic capacity threshold, then vehicles at the key exits of the secondary road are allowed to pass.

5. A traffic signal response method for the vicinity of a traffic accident according to claim 2, characterized in that, The step of creating a traffic gap on the road segment upstream of the target intersection includes: Control the red light duration of the main road traffic lights at the intersection upstream of the target intersection; Obtain the vehicle density of the road segment upstream of the target intersection; Determine whether the vehicle density has reached a preset low-density state; When the vehicle density does not reach the preset low density state, the red light duration of the main road direction traffic lights at the intersection upstream of the target intersection is adjusted until the vehicle density reaches the preset low density state, so as to create a traffic gap in the road section upstream of the target intersection.

6. A traffic signal response method for the vicinity of a traffic accident according to claim 5, characterized in that, The step of obtaining the vehicle density of the road segment upstream of the target intersection includes: Obtain vehicle presence information for the road segment upstream of the target intersection; Identify non-moving vehicles and non-motorized vehicles in the vehicle presence information of the road segment upstream of the target intersection; Excluding the non-moving vehicles and non-motorized vehicles in the vehicle presence information of the road segment upstream of the target intersection, the vehicle presence information upstream of the target intersection is obtained; Based on the vehicle presence information upstream of the target intersection, calculate the vehicle density of the road segment upstream of the target intersection.

7. A traffic signal response method for the vicinity of a traffic accident according to claim 1, characterized in that, After vehicles have exited the secondary road at the critical exit have completed their passage, the steps of determining that the emergency situation has been resolved and restoring traffic signal control based on a preset initial signal include: Obtain information on vehicle passage completion at key exits of secondary roads; Based on the passage completion information, the emergency situation is determined to be resolved; After the emergency is over, the signal control units at the target intersection and related intersections are switched from emergency mode to initial mode. Load the preset timing scheme corresponding to the initial signal to restore traffic signal control.

8. A traffic signal response method for the vicinity of a traffic accident according to claim 1, characterized in that, The steps of obtaining the main road traffic flow parameters and the vehicle presence information at the exits of secondary roads include: Acquire raw traffic data from various types of traffic sensors within the area affected by a traffic accident; The quality of the raw traffic data is assessed. Based on the results of the quality assessment, sensor data is filtered to obtain advanced sensor data; The advanced sensor data is fused and verified to generate the final traffic data; Based on the final traffic data, traffic flow parameters for the main traffic arteries and vehicle presence information at the exits of secondary traffic roads are generated.

9. A traffic signal response system for the area surrounding a traffic accident, used to execute traffic signal responses around a traffic accident, characterized in that, include: The parameter information acquisition module is used to acquire the main traffic flow parameters of the main traffic artery and the vehicle presence information at the exits of the secondary traffic arteries. The main road status judgment module is used to determine whether the main road is in a congested state based on the main road traffic flow parameters, and to obtain the main road status judgment result. The secondary road status judgment module is used to determine whether the secondary road is in an abnormal congestion state at the secondary road exit based on the vehicle presence information at the secondary road exit, and to obtain the secondary road status judgment result. The obstruction event identification module is used to identify and record a passive obstruction event at a critical exit when both the main road status judgment result and the secondary road status judgment result indicate yes. The emergency response execution module is used to initiate an emergency response after recording a passive obstruction event at a key exit, and send a control command to the intersection upstream of the target intersection corresponding to the passive obstruction event, so that the traffic lights on the main road at the intersection upstream of the target intersection are set to red, thereby creating a traffic gap on the road section upstream of the target intersection. The vehicle clearing execution module is used to turn the main road direction traffic light of the target intersection to green after the traffic gap is created, and clear the vehicles in the main road area in front of the key exit of the secondary road. The steps for clearing vehicles from the main road area ahead of the critical exit of the secondary road include: Turn the traffic light for the main road at the target intersection to green; Obtain vehicle presence information in the area of ​​the main road ahead of the key exit of the secondary road; Based on the vehicle presence information, determine the clearance status of the main road area in front of the key exit of the secondary road; When the clearing state does not meet the preset clearing conditions, the green light duration of the main road direction traffic light at the target intersection is extended until the clearing state meets the preset clearing conditions. After the clearing state reaches the preset clearing conditions, the system continuously acquires information on the presence of subsequent vehicles in the main road area ahead of the key exit of the secondary road. When subsequent vehicle information indicates that a vehicle is re-entering the main road area ahead of the key exit of the secondary road, the green light duration of the main road direction signal light at the target intersection will be extended again. The vehicle release execution module is used to release vehicles at the key exit of the secondary road after confirming that the area of ​​the main road in front of the key exit of the secondary road has been cleared. The traffic signal restoration module is used to determine that the emergency situation has been resolved and restore traffic signal control based on the preset initial signal after vehicles have been allowed to pass through the key exits of the secondary road.

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