Response method and system for traffic signals around traffic accident

Abstract

The invention relates to the technical field of traffic signal control, and provides a traffic accident surrounding traffic signal response method and system, and the method comprises the steps: obtaining main road traffic flow parameters and secondary road exit vehicle existence information; judging whether the trunk road is in a trunk road congestion state or not; judging whether the secondary road is in a secondary road exit abnormal retention state or not; identifying a key exit passive blocking event; a control instruction is sent to an upstream intersection of the target intersection corresponding to the key exit passive blocking event, so that the upstream intersection of the target intersection controls a main road direction signal lamp to be red, and a traffic gap is created; turning the signal lamp in the main road direction of the target intersection into green light, and emptying vehicles in the main road area in front of the key exit of the secondary road; after it is confirmed that the vehicle is emptied, the vehicle at the key exit is released; and after the release is completed, judging that the emergency condition is relieved and recovering traffic signal control. The method has the advantage of avoiding traffic delay and potential public safety risks.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of traffic signal control, and in particular to a traffic accident surrounding traffic signal response method and system. BACKGROUND

[0002] Current urban traffic management is facing increasingly complex challenges, especially in the case of local traffic congestion caused by sudden traffic accidents. Traditional traffic signal control systems usually take improving the efficiency of main road traffic as the core goal, but in some specific scenarios, its inherent optimization strategy may lead to unexpected negative consequences.

[0003] For example, when the main road is congested due to an accident, and the congestion spreads upstream, physically blocking the exit of the secondary road connecting important emergency facilities, existing systems often fail to accurately identify this special and high-risk situation. These systems may misjudge the long-time detention of high-priority vehicles at the secondary road exit as low traffic demand, and continue to prioritize the traffic of the main road, resulting in serious delays in emergency response, and even may cause public safety crises. The dual effects of physical blockage and signal control logic misjudgment make the vehicles at the critical exit passively blocked and unable to enter the main road in time, which seriously hinders their task execution and poses a potential threat to urban operation and public safety.

[0004] In view of the above problems, the existing technology needs to be improved. SUMMARY

[0005] In order to solve the problems of the prior art, the present application provides a traffic accident surrounding traffic signal response method and system, which can effectively identify and respond to the situation of passive blocking of critical exit of secondary road caused by traffic accident, ensure the timely passage of emergency vehicles or high-priority vehicles, and avoid traffic delays and potential public safety risks.

[0006] The present application provides a traffic accident surrounding traffic signal response method, comprising: obtaining main road traffic flow parameters of a traffic main road and secondary road exit vehicle existence information of a traffic secondary road; judging whether the main road is in a main road congestion state according to the main road traffic flow parameters, to obtain a main road state judgment result; judging whether the secondary road is in a secondary road exit abnormal detention state according to the secondary road exit vehicle existence information, to obtain a secondary road state judgment result; when the main road state judgment result and the secondary road state judgment result both indicate yes, identifying and recording as a critical exit passive blocking event; After recording the key exit passive blockage event, an emergency response is started, control instructions are sent to the intersections upstream of the target intersection corresponding to the key exit passive blockage event, the signal lights in the main road direction of the intersections upstream of the target intersection are controlled to be red, so as to create a traffic gap on the road segment upstream of the target intersection; After the traffic gap is created, the signal lights in the main road direction of the target intersection are turned to green, and the vehicles in the main road area in front of the key exit of the secondary road are emptied; After confirming that the main road area in front of the key exit of the secondary road has been emptied, the vehicles of the key exit of the secondary road are released; After the release of the vehicles of the key exit of the secondary road is completed, it is determined that the emergency situation is removed, and the traffic signal control is restored based on the preset initial signal.

[0007] Through the above scheme, the passive blockage of the key exit of the secondary road caused by the traffic accident can be effectively identified and responded, the timely passage of the emergency vehicle or the high-priority vehicle is ensured, and the traffic delay and the potential public safety risk are avoided.

[0008] To further solve the problem, the application also provides that after recording the key exit passive blockage event, an emergency response is started, control instructions are sent to the intersections upstream of the target intersection corresponding to the key exit passive blockage event, the signal lights in the main road direction of the intersections upstream of the target intersection are controlled to be red, so as to create a traffic gap on the road segment upstream of the target intersection, and the steps include: An emergency silence instruction is sent to the intersection upstream of the target intersection corresponding to the key exit passive blockage event; The emergency silence instruction makes the signal control unit of the intersection upstream of the target intersection enter an emergency silence state; After entering the emergency silence state, the signal control unit stops responding to the vehicle detector input signal related to the road segment upstream of the target intersection, and locks the signal light to the target road segment to be red, so as to create a traffic gap on the road segment upstream of the target intersection.

[0009] Through the above scheme, the specific emergency silence instruction and signal control logic for creating a traffic gap are further clarified, and the accuracy and efficiency of the emergency response are improved.

[0010] To perfect the solution, the application also provides that the step of emptying the vehicles in the main road area in front of the key exit of the secondary road includes: The signal lights in the main road direction of the target intersection are turned to green; The vehicle existence information of the main road area in front of the key exit of the secondary road is obtained; According to the vehicle existence information, the emptying state of the main road area in front of the key exit of the secondary road is determined; When the emptying state does not reach the preset emptying condition, the green light duration of the main road direction signal light of the target intersection is extended until the emptying state reaches the preset emptying condition; After the emptying state reaches the preset emptying condition, the subsequent vehicle existence information of the main road area in front of the key exit of the secondary road is continuously acquired; When the subsequent vehicle existence information shows that the main road area in front of the key exit of the secondary road has vehicles entering again, the green light duration of the main road direction signal light of the target intersection is extended again.

[0011] Through the above scheme, the strategy of emptying the main road area is described in detail, the green light duration is dynamically extended to ensure complete emptying, and the situation of subsequent vehicles entering again is handled, thereby improving the effectiveness of the emptying operation.

[0012] To further solve the problem, the application also provides that the step of determining the emptying state of the main road area in front of the key exit of the secondary road according to the vehicle existence information comprises: According to the vehicle existence information, the actual emptying space of the main road area in front of the key exit of the secondary road is acquired; The size information of the vehicle waiting at the key exit of the secondary road is acquired; According to the size information, the required minimum emptying space of the main road area in front of the key exit of the secondary road is determined; The actual emptying space and the required minimum emptying space are compared to determine the emptying state of the main road area in front of the key exit of the secondary road.

[0013] Through the above scheme, the determination method of the emptying state is further refined, and by comparing the actual emptying space with the required minimum emptying space, the emptying determination is more accurate and intelligent.

[0014] To perfect the solution, the application also provides that after confirming that the main road area in front of the key exit of the secondary road has been emptied, the step of releasing the vehicle at the key exit of the secondary road comprises: After confirming that the main road area in front of the key exit of the secondary road has been emptied, the traffic flow state information of the road section downstream of the key exit of the secondary road is acquired; According to the traffic flow state information, the traffic capacity of the road section downstream of the key exit of the secondary road is determined; If the traffic capacity is less than a preset traffic capacity threshold, the vehicle at the key exit of the secondary road is delayed to be released; If the traffic capacity is greater than or equal to the preset traffic capacity threshold, the vehicle at the key exit of the secondary road is released.

[0015] Through the above scheme, the downstream road section passing capacity before the secondary road vehicle is released is determined, and downstream congestion caused immediately after the secondary road vehicle is released is avoided, and the overall traffic flow is optimized.

[0016] To further solve the problem, the application further provides that the step of manufacturing a traffic gap on the road section upstream of the target intersection comprises: controlling the red light duration of the intersection trunk road direction signal light of the road section upstream of the target intersection; obtaining the vehicle density of the road section upstream of the target intersection; determining whether the vehicle density reaches a preset low density state; When the vehicle density does not reach the preset low density state, the red light duration of the intersection trunk road direction signal light of the road section upstream of the target intersection is adjusted until the vehicle density reaches the preset low density state, so as to manufacture a traffic gap on the road section upstream of the target intersection.

[0017] Through the above scheme, the control strategy of traffic gap manufacturing is further refined, and the effective formation of the traffic gap is ensured by dynamically adjusting the red light duration until the vehicle density reaches the preset low density state.

[0018] To perfect the solution, the application further provides that the step of obtaining the vehicle density of the road section upstream of the target intersection comprises: obtaining vehicle existence information of the road section upstream of the target intersection; identifying non-moving vehicles and non-motor vehicles in the vehicle existence information of the road section upstream of the target intersection; excluding the non-moving vehicles and non-motor vehicles in the vehicle existence information of the road section upstream of the target intersection to obtain target intersection upstream vehicle existence information; According to the target intersection upstream vehicle existence information, the vehicle density of the road section upstream of the target intersection is calculated.

[0019] Through the above scheme, the accurate method of obtaining the vehicle density is determined, and the accuracy of the vehicle density calculation is improved by excluding the non-moving vehicles and non-motor vehicles, so that the manufacturing of the traffic gap is more accurate.

[0020] To further solve the problem, the application further provides that after the vehicle of the key exit of the secondary road is released, the step of determining that the emergency condition is removed and restoring the traffic signal control based on the preset initial signal comprises: obtaining the passing completion information of the vehicle at the key exit of the secondary road; According to the passing completion information, it is determined that the emergency condition is removed; After the emergency condition is removed, the signal control unit of the target intersection and the related intersection is switched from the emergency mode to the initial mode; Load the preset timing scheme corresponding to the initial signal to restore the traffic signal control.

[0021] Through the above scheme, the process of emergency situation release and traffic signal recovery is described in detail, ensuring that the system can smoothly switch back to normal mode from emergency mode, avoiding secondary congestion.

[0022] To perfect the solution, the application also provides that the step of obtaining the main road traffic flow parameters of the main road and the secondary road exit vehicle existence information of the secondary road includes: Obtain the original traffic data from various types of traffic sensors in the traffic accident area; Quality assessment of the original traffic data; According to the result of quality assessment, the sensor data is screened to obtain advanced sensor data; Fusion and verification of advanced sensor data to generate final traffic data; According to the final traffic data, the main road traffic flow parameters of the main road and the secondary road exit vehicle existence information of the secondary road are generated.

[0023] Through the above scheme, the detailed data processing flow of obtaining traffic flow parameters and vehicle existence information is provided, including data quality assessment, screening, fusion and verification, ensuring the accuracy and reliability of the input data.

[0024] To further solve the problem, the application also provides a traffic accident surrounding traffic signal response system for executing traffic accident surrounding traffic signal response, comprising: Parameter information acquisition module, for obtaining the main road traffic flow parameters of the main road and the secondary road exit vehicle existence information of the secondary road; Main road state judgment module, for judging whether the main road is in the main road congestion state according to the main road traffic flow parameters, to obtain the main road state judgment result; Secondary road state judgment module, for judging whether the secondary road is in the secondary road exit abnormal retention state according to the secondary road exit vehicle existence information, to obtain the secondary road state judgment result; Blocked event identification module, for identifying and recording as a key exit passive blocked event when the main road state judgment result and the secondary road state judgment result are both yes; Emergency response execution module, for starting emergency response after recording the key exit passive blocked event, sending control instructions to the intersection upstream of the target intersection corresponding to the key exit passive blocked event, making the intersection upstream of the target intersection control the main road direction signal lamp to red, to create traffic gap in the road section upstream of the target intersection; A vehicle emptying execution module is configured to turn the main road direction signal light at the target intersection to green after the traffic gap is created, and to empty the vehicles in the main road area in front of the key exit of the secondary road; A vehicle releasing execution module is configured to release the 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 is emptied. A traffic signal recovery module is configured to determine that the emergency situation is removed after the vehicles at the key exit of the secondary road are released, and to recover the traffic signal control based on the preset initial signal.

[0025] Through the above scheme, a system for implementing the above method is provided, so that the method can be actually deployed and executed, and has good operability and practicability.

[0026] In summary, the traffic accident surrounding traffic signal response method and system provided by the present application can effectively identify and respond to the passive blocking situation of the key exit of the secondary road caused by the traffic accident, ensure the timely passage of emergency vehicles or high-priority vehicles, and avoid traffic delays and potential public safety risks. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A method flowchart of a traffic accident surrounding traffic signal response method in one embodiment of the present application; Figure 2 One of the method flowcharts of a traffic accident surrounding traffic signal response method in another embodiment of the present application; Figure 3 The second method flowchart of a traffic accident surrounding traffic signal response method in another embodiment of the present application; Figure 4 The third method flowchart of a traffic accident surrounding traffic signal response method in another embodiment of the present application; Figure 5 The fourth method flowchart of a traffic accident surrounding traffic signal response method in another embodiment of the present application; Figure 6 The fifth method flowchart of a traffic accident surrounding traffic signal response method in another embodiment of the present application; Figure 7 The sixth method flowchart of a traffic accident surrounding traffic signal response method in another embodiment of the present application; Figure 8 The seventh method flowchart of a traffic accident surrounding traffic signal response method in another embodiment of the present application; Figure 9Figure 8 is a flow chart of a method for a traffic accident surrounding traffic signal response method according to another embodiment of the present application; Figure 10 Figure 9 is a system block diagram of a traffic accident surrounding traffic signal response system according to another embodiment of the present application; Explanation of reference signs: 1, traffic accident surrounding traffic signal response system; 11, parameter information acquisition module; 12, main road state judgment module; 13, secondary road state judgment module; 14, blocked event identification module; 15, emergency response execution module; 16, vehicle emptying execution module; 17, vehicle release execution module; 18, traffic signal recovery module. DETAILED DESCRIPTION

[0028] The technical solutions in the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. The components of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0029] It should be noted that: similar signs and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of the present application, the terms "first", "second" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0030] The conventional existing traffic signal control system cannot effectively identify the situation that the main road congestion physically blocks the high-priority secondary road exit when dealing with the main road congestion caused by traffic accidents, which leads to the failure to take timely targeted measures to remove the blockage, thereby affecting the traffic efficiency of the secondary road.

[0031] To this end, the present application proposes a traffic accident surrounding traffic signal response method, which combines Figure 1 As shown in the figure, comprising: S1, obtaining the main road traffic flow parameters of the main road and the secondary road exit vehicle existence information of the secondary road; S2, judging whether the main road is in the main road congestion state according to the main road traffic flow parameters, and obtaining the main road state judgment result; S3, judging whether the secondary road is in the secondary road exit abnormal stay state according to the secondary road exit vehicle existence information, obtaining a secondary road state judgment result; S4, when the main road state judgment result and the secondary road state judgment result both indicate yes, identifying and recording as a key exit passive obstruction event; S5, after recording the key exit passive obstruction event, starting an emergency response, sending a control instruction to the intersection upstream of the target intersection corresponding to the key exit passive obstruction event, making the intersection upstream of the target intersection control the main road direction signal lamp to red, so as to create a traffic gap on the road segment upstream of the target intersection; S6, after the traffic gap is created, making the main road direction signal lamp of the target intersection turn to green, and emptying the vehicles in the main road area in front of the key exit of the secondary road; S7, after confirming that the main road area in front of the key exit of the secondary road has been emptied, releasing the vehicles of the key exit of the secondary road; S8, after the release of the vehicles of the key exit of the secondary road is completed, determining that the emergency situation is resolved and restoring the traffic signal control based on the preset initial signal.

[0032] The main road traffic flow parameter of the main road is a data set reflecting the traffic condition of the main road, which can be realized by various traffic detection technologies, such as vehicle flow, vehicle speed, occupancy rate detected by a buried inductive coil, or vehicle queue length, average vehicle speed obtained by video detector analysis, etc., which is mainly to obtain the real-time traffic operation of the main road, and to provide a data basis for judging whether the main road is congested. The secondary road exit vehicle existence information of the secondary road is a signal or data indicating whether there is a vehicle waiting to pass at the secondary road exit, which can be realized by various sensor technologies, such as detecting a vehicle pressure signal by a ground inductive coil, identifying vehicle existence by image recognition technology, or detecting a vehicle by ultrasonic or radar sensor, which is mainly to monitor whether there is a vehicle stranded at the secondary road exit, and to provide a basis for judging whether the secondary road exit is abnormally stranded. The main road congestion state is the traffic operation state when the main road traffic flow parameter reaches or exceeds the preset threshold, such as vehicle speed below a certain value, vehicle density above a certain value, queue length exceeding a certain length, etc., which is mainly to accurately identify whether the main road is congested, which is one of the prerequisite conditions for triggering subsequent emergency response. The secondary road exit abnormal stranded state is a state in which a vehicle exists at the secondary road exit for a long time and cannot normally drive off, which can be judged according to the vehicle existence information combined with time threshold, vehicle movement state, etc., such as the vehicle staying at the exit for more than a preset time and no obvious movement, which is mainly to identify the abnormal stranded situation of the vehicle at the secondary road exit, which together with the main road congestion constitutes the judgment basis for the key exit passive obstruction event. The key exit passive obstruction event is a specific traffic event in which the main road is in a congested state while the secondary road exit is in an abnormal stranded state, which is mainly to accurately identify the emergency situation that the key exit of the secondary road is physically blocked due to the congestion of the main road, so as to trigger targeted emergency response. The traffic gap is a section of no vehicle or very low vehicle density area on the main road upstream of the target intersection, which can be realized by controlling the upstream signal lamp to be red, such as prolonging the red light time to prevent vehicles from entering the section, which is mainly to create enough space on the main road in front of the target intersection, so that the vehicles of the secondary road can safely and smoothly merge into the main road.

[0033] In some preferred embodiments, the application is implemented as follows. The system can obtain the traffic flow parameters of the main road, such as vehicle flow, average speed, lane occupancy and queue length, in real time through the buried inductive coil array and high-position video detector deployed on the main road. At the same time, at the exit of the secondary road, an independent inductive coil or a small millimeter wave radar sensor can be installed to continuously detect whether there is a vehicle staying in the exit area, thereby obtaining the vehicle presence information at the exit of the secondary road. When judging the congestion state of the main road, the system can set a dynamic threshold, for example, when the average speed of a certain section of the main road is less than 15 kilometers per hour for three consecutive signal periods, and the lane occupancy rate is more than 80%, it is judged that the main road is in a congested state. For the judgment of the abnormal stay state of the exit of the secondary road, the system can set that if the vehicle presence information at the exit of the secondary road shows that a vehicle has been continuously present for more than 30 seconds, and there is no obvious displacement of the vehicle in the detection area, it is judged as abnormal stay. When the two conditions are met at the same time, the system identifies and records it as a key exit passive obstruction event. Once the event is identified, the emergency response module will immediately send an instruction to the traffic signal control unit upstream of the target intersection. For example, the instruction can be a "forced red light" signal, which makes the main road direction signal of the upstream intersection turn red immediately and keep it for at least 60 seconds to ensure that a traffic gap is created on the section upstream of the target intersection, which is long enough to accommodate the vehicles waiting to be released at the exit of the secondary road. After the traffic gap is created, the main road direction signal of the target intersection will turn green, and the duration can be dynamically adjusted according to the vehicle emptying situation in the main road area in front of the exit of the secondary road, for example, through video analysis or ground inductive coil feedback, when the vehicle density in this area decreases to a preset extremely low level (for example, less than 5 vehicles per hundred meters), it is considered that the emptying is completed. After confirming that the emptying is completed, the system sends a green light instruction to the key exit signal of the secondary road to release the waiting vehicles. After the release is completed, the system receives the feedback signal that all vehicles on the secondary road have passed, at which point it is determined that the emergency situation is resolved, and the signal control unit of the target intersection and related intersections is switched from emergency mode back to normal mode, loads the preset daily timing scheme, and restores normal traffic signal control.

[0034] Optionally, in combination with Figure 2 As shown in S5, after recording the key exit passive obstruction event, the emergency response is started, and a control instruction is sent to the intersection upstream of the target intersection corresponding to the key exit passive obstruction event, so that the intersection upstream of the target intersection controls the main road direction signal to be red to create a traffic gap on the section upstream of the target intersection. The step includes: S51, an emergency silence instruction is sent to the intersection upstream of the target intersection corresponding to the key exit passive obstruction event; S52, the emergency silence instruction makes the signal control unit of the intersection upstream of the target intersection enter an emergency silence state; S53, after entering the emergency mute state, the signal control unit suspends responding to the vehicle detector input signals related to the road segment upstream of the target intersection, and locks the signal light leading to the target road segment to the red state to create a traffic gap on the road segment upstream of the target intersection.

[0035] Wherein, the emergency mute instruction refers to a special, high-priority control command, whose purpose is to make the traffic signal control system deviate from the regular signal timing logic and enter a pre-set emergency handling mode, which can be sent in the form of data packets, special coded signals or dedicated communication protocols, etc. The signal control unit refers to a collection of hardware and software responsible for managing and controlling traffic signal lights, usually deployed at intersections or regional traffic control centers, which can be a standalone controller, an embedded system or a node in a distributed control network. The emergency mute state refers to a non-standard operating mode that the signal control unit enters after receiving the emergency mute instruction, in which mode the signal control unit will suspend or ignore the regular traffic flow detection data input and enforce the pre-set emergency signal control strategy. Suspending responding to the vehicle detector input signals related to the road segment upstream of the target intersection refers to the signal control unit, in the emergency mute state, stopping processing or ignoring real-time traffic data provided by vehicle detection devices (such as inductive loops, video detectors, radar detectors, etc.) related to a specific road segment (i.e. the road segment leading to the upstream of the target intersection), whose purpose is to avoid the interference of regular traffic demand judgment on emergency signal control. Locking the signal light leading to the target road segment to the red state refers to the signal control unit, in the emergency mute state, forcibly setting the traffic signal light in a specific direction (i.e. leading to the target road segment) to red and not changing with regular signal timing or real-time traffic data, whose purpose is to ensure that vehicles in that direction stop passing, thereby providing conditions for creating a traffic gap.

[0036] In some preferred embodiments, the present solution is implemented as follows: when the system identifies a critical exit passive congestion event, for example, through the master server of the traffic management center, a pre-defined emergency mute instruction is sent to the intelligent traffic signal controller deployed at the intersection upstream of the target intersection. The instruction can be a TCP / IP data packet containing specific identifiers and control parameters, transmitted to the target controller through a fiber optic network or a wireless communication module. After receiving the emergency mute instruction, the signal control unit inside the intelligent traffic signal controller, such as its main processor or dedicated control chip, will immediately parse the instruction and switch its internal operating mode from the regular timing mode to the emergency mute state. After entering the emergency mute state, the signal control unit will stop processing real-time input signals from vehicle detection devices such as ground coils, video detectors, or radar detectors related to the road segment leading to the 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 signal light state based on this information. At the same time, the signal control unit will directly send instructions to the output module controlling the signal lights leading to the target road segment, forcibly setting the signal lights in that direction to red and maintaining that red state until the emergency mute state is lifted. For example, by directly controlling relays or solid-state switches, it can be ensured that the red light remains on, preventing vehicles from entering the road segment and creating the required traffic gap upstream of the target intersection.

[0037] Optionally, in combination with Figure 3 As shown in FIG. 6, the step of emptying the vehicles in the main road area in front of the critical exit of the secondary road in step S6 includes: S61, turning the main road direction signal light of the target intersection to green; S62, obtaining vehicle presence information in the main road area in front of the critical exit of the secondary road; S63, determining the emptying state of the main road area in front of the critical exit of the secondary road according to the vehicle presence information; S64, when the emptying state does not meet the pre-set emptying condition, extending the green light duration of the main road direction signal light of the target intersection until the emptying state meets the pre-set emptying condition; S65, after the emptying state meets the pre-set emptying condition, continuously obtaining subsequent vehicle presence information in the main road area in front of the critical exit of the secondary road; S66, when the subsequent vehicle presence information shows that vehicles have re-entered the main road area in front of the critical exit of the secondary road, the green light duration of the main road direction signal light of the target intersection is extended again.

[0038] The vehicle presence information refers to the data about the number, position, speed, queue length, etc. of vehicles in a specific area collected in real time by various traffic sensors (e.g. induction coils, video detectors, radar sensors, etc.), which aims to provide a real-time snapshot of the traffic conditions in the area. The empty state refers to the quantitative evaluation of the vehicle situation in the main road area in front of the key exit of the secondary road, which is used to determine whether the area has reached the condition that can be used for the secondary road vehicle to pass, which can be specifically determined by analyzing the vehicle presence information, such as calculating the number of vehicles, vehicle density, or average speed of vehicles in the area, etc. The purpose is to provide a basis for subsequent signal light control decisions. The preset empty condition refers to the threshold or standard preset for determining whether the area has reached a sufficient empty degree when emptying the main road area in front of the key exit of the secondary road, which can be specifically set as the number of vehicles in the area being lower than a certain specific value, or the vehicle density of the area being lower than a certain threshold, or the average speed of the vehicles in the area being higher than a certain threshold, or even no vehicles existing in the area, which aims to ensure that the secondary road vehicles have enough space to safely enter the main road. The subsequent vehicle presence information refers to the real-time data about the vehicle situation in the area continuously obtained by the system after the main road area in front of the key exit of the secondary road reaches the preset empty condition, which aims to monitor whether new vehicles have entered the already emptied area again to prevent the emptying effect from being destroyed.

[0039] In some preferred embodiments, the clearing of the arterial road area in front of the critical exit of the secondary road can be implemented as follows: first, when the traffic gap is created, the arterial road direction signal at the target intersection is turned green by the control unit, allowing arterial road vehicles to pass. Then, the vehicle presence information of the arterial road area in front of the critical exit can be obtained in real time by the high-precision video detectors and inductive coils deployed in this area. These information includes but is not limited to the number of vehicles in this area, the average speed of vehicles and the queuing length of vehicles. Next, a processing module in a central traffic management system will determine the clearing state of the arterial road area in front of the critical exit of the secondary road according to these vehicle presence information. For example, the processing module can calculate the vehicle density of this area, or evaluate the available space of this area. When the clearing state does not meet the preset clearing condition (for example, the vehicle density of this area is still higher than 10 vehicles per kilometer, or the available space is not enough to accommodate an emergency vehicle), the processing module will send instructions to the signal control unit of the target intersection to extend the green time of the arterial road direction signal. This extension process will continue, for example, 5 seconds each time, until the vehicle density of this area is reduced to less than 5 vehicles per kilometer, or the available space meets the preset standard. After the clearing state meets the preset clearing condition, the video detectors and inductive coils will continue to send subsequent vehicle presence information to the central traffic management system to monitor the traffic conditions of this area in real time. If the subsequent vehicle presence information shows that the arterial road area in front of the critical exit of the secondary road has vehicles entering again (for example, the vehicle density rises again to more than 8 vehicles per kilometer), the processing module will immediately send instructions to the signal control unit again to extend the green time of the arterial road direction signal again to ensure that the area is kept clear before the vehicles of the secondary road are released.

[0040] Optionally, in combination with Figure 4 As shown in FIG. 6, the step of determining the clearing state of the arterial road area in front of the critical exit of the secondary road according to the vehicle presence information includes: S631, obtaining the actual clearing space of the arterial road area in front of the critical exit of the secondary road according to the vehicle presence information; S632, obtaining the size information of the vehicle waiting at the critical exit of the secondary road; S633, determining the required minimum clearing space of the arterial road area in front of the critical exit of the secondary road according to the size information; S634, comparing the actual clearing space with the required minimum clearing space to determine the clearing state of the arterial road area in front of the critical exit of the secondary road.

[0041] The actual clearance space refers to the size of the unobstructed space currently available for vehicle travel in the main road area in front of the key exit of the secondary road. It can be obtained by analyzing the vehicle position, spacing, and motion trajectory based on sensor data such as visual recognition, radar detection, or laser scanning, and calculating the continuous and available net length or area in the area in real time. The purpose is to quantify the actual available space provided by the main road for the merging of secondary road vehicles. The size information refers to the physical size data of the vehicle waiting to enter the main road at the key exit of the secondary road, such as the length, width, or vehicle type category. It can be obtained by classifying and estimating the size of the vehicle based on image recognition technology, or by matching the vehicle detector with a pre-set vehicle model library. The purpose is to accurately assess the minimum space required for the waiting vehicle to merge into the main road. The required minimum clearance space refers to the minimum unobstructed space that must be provided in the area in front of the main road to ensure that the waiting vehicle at the key exit of the secondary road can safely and smoothly merge into the main road. It can be determined by looking up tables, formula calculation, or dynamic programming based on the size information of the waiting vehicle, combined with pre-set safety margins, turning radii, or merging path models. The purpose is to provide an objective and dynamic measurement standard for the clearance state determination, ensuring safe merging. The clearance state refers to whether the main road area in front of the key exit of the secondary road has reached the condition sufficient for safely releasing secondary road vehicles. It can be obtained by logically comparing the actual clearance space with the required minimum clearance space, such as determining whether the actual clearance space is greater than or equal to the required minimum clearance space. The purpose is to provide a clear decision basis to determine whether secondary road vehicles can be released.

[0042] In some preferred embodiments, the determination of the clearance status of the arterial road region in front of the critical exit of the secondary road can be implemented as follows. First, to obtain the actual clearance space of the arterial road region in front of the critical exit of the secondary road, video detectors or millimeter-wave radars installed above the arterial road can be utilized. These sensors continuously monitor the vehicle distribution and movement of the region, identify the gaps between vehicles through image processing algorithms or radar signal analysis, and calculate the length or area of these gaps to obtain the actual clearance space. For example, if a continuous, vehicle-free region with a length exceeding a preset threshold is detected, it is considered that there is available clearance space. Meanwhile, to obtain the size information of the waiting vehicles at the critical exit of the secondary road, a roadside laser scanner or high-precision camera can be used in combination with a vehicle recognition algorithm to classify the waiting vehicles by vehicle type and estimate their approximate sizes. These size information can include the length and width of the vehicles. Then, according to the size information of the waiting vehicles obtained, the system can consult a preset size-space requirement table or use a dynamic calculation model to determine the required minimum clearance space of the arterial road region in front of the critical exit of the secondary road. For example, for a waiting truck, the required minimum clearance space will be larger than that for a car, which takes into account the turning radius and safety distance. Finally, the actual clearance space calculated in real time is compared with the required minimum clearance space determined according to the size of the waiting vehicles. If the actual clearance space is greater than or equal to the required minimum clearance space, it is determined that the region has reached the clearance state and the secondary road vehicles can be safely released; otherwise, it is determined that it is not clear, and the arterial road green light duration needs to be extended to create enough clearance space.

[0043] Optionally, in combination with Figure 5 As shown in FIG. 7, the step of releasing the vehicles at the critical exit of the secondary road after confirming that the arterial road region in front of the critical exit of the secondary road is clear includes: S71, after confirming that the arterial road region in front of the critical exit of the secondary road is clear, obtaining traffic flow state information of a road segment downstream of the critical exit of the secondary road; S72, determining the traffic capacity of the road segment downstream of the critical exit of the secondary road according to the traffic flow state information; S73, if the traffic capacity is less than a preset traffic capacity threshold, delaying the release of the vehicles at the critical exit of the secondary road; S74, if the traffic capacity is greater than or equal to the preset traffic capacity threshold, releasing the vehicles at the critical exit of the secondary road.

[0044] The traffic flow state information refers to a data set reflecting the current traffic operating conditions of a specific road section, which can be characterized by parameters such as vehicle speed, vehicle density, lane occupancy, queue length, and travel time. The traffic capacity refers to the maximum number of vehicles that can safely and smoothly pass through a specific road section within a given time, which can be calculated based on the traffic flow state information, for example, by analyzing the relationship between vehicle density and speed. The traffic capacity threshold refers to a preset reference value for determining whether the road section has sufficient traffic space, which serves as a basis for decision-making on whether to release vehicles from the secondary road, and can be set according to road design standards, historical traffic data, or real-time traffic management strategies.

[0045] In some preferred embodiments, the application is implemented as follows: After confirming that the main road area in front of the key exit of the secondary road has been cleared, the traffic management system can obtain the traffic flow state information of the road section downstream of the key exit of the secondary road through various sensors. For example, the flow, speed, occupancy, and other data of vehicles can be collected in real time using loop detectors, video detectors, or radar sensors installed on the downstream road section. These raw data are transmitted to the central processing unit for data fusion and analysis to generate accurate traffic flow state information.

[0046] Specifically, the central processing unit can calculate the vehicle density of the downstream road section based on the collected vehicle flow and road section length, and further evaluate the traffic capacity of the road section in combination with the average speed of the vehicles. For example, when the vehicle density exceeds 30 vehicles per kilometer and the average speed is less than 20 kilometers per hour, it can be preliminarily judged that the traffic capacity is low. The system compares the calculated traffic capacity with the preset traffic capacity threshold. This threshold can be dynamically adjusted according to the road grade, design speed, and historical traffic data, for example, for urban main roads, the traffic capacity threshold can be set to 1500 vehicles per lane per hour.

[0047] If the calculated traffic capacity is lower than this threshold, for example, only 800 vehicles per lane per hour, the system will issue a delay release instruction, keeping the signal light of the key exit of the secondary road red or extending the duration of its red state. The system will continuously monitor the traffic flow state information of the downstream road section until the traffic capacity recovers to or exceeds the preset threshold. Once the traffic capacity reaches or exceeds the threshold, for example, it recovers to 1600 vehicles per lane per hour, the system will immediately issue a release instruction to turn the signal light of the key exit of the secondary road to green, allowing the waiting vehicles to safely merge into the main road. This dynamic decision-making mechanism based on the traffic capacity of the downstream road section ensures that the release of vehicles from the secondary road is carried out under the premise that the overall traffic flow of the main road is controllable and safe.

[0048] Optionally, in combination with Figure 6As shown, the step of manufacturing traffic gap on the road section upstream of the target intersection in step S53 includes: S531, controlling the red light duration of the intersection trunk road direction signal light of the road section upstream of the target intersection; S532, obtaining the vehicle density of the road section upstream of the target intersection; S533, judging whether the vehicle density reaches the preset low density state; S534, when the vehicle density does not reach the preset low density state, adjusting the red light duration of the intersection trunk road direction signal light of the road section upstream of the target intersection until the vehicle density reaches the preset low density state, to manufacture traffic gap on the road section upstream of the target intersection.

[0049] Wherein, the vehicle density refers to the number of vehicles existing in a unit length of a specific road section, which can be calculated by using vehicle existing information obtained by inductive coils, video detectors, radar sensors or floating car data, etc. The preset low density state refers to a threshold state that is preset to represent the sparsity of road traffic flow or the small number of vehicles, which can be a vehicle density value, for example, the number of vehicles per kilometer is less than a certain specific value, or a state determined based on comprehensive indicators such as traffic capacity and queue length, the purpose of which is to ensure that sufficient space is formed on the target road section so that vehicles on the secondary road can smoothly merge into the trunk road.

[0050] In some preferred embodiments, when the system identifies a critical exit blocked event and initiates an emergency response, the signal control unit of the intersection upstream of the target intersection receives an emergency mute instruction and enters an emergency mute state. At this time, the signal control unit will first set the signal light of the main road direction to red and set an initial red light duration, for example, 30 seconds. At the same time, multiple traffic sensors deployed on the road segment upstream of the target intersection, such as inductive coil arrays or high-definition video detectors, continuously collect real-time traffic data of the road segment, including the number of vehicles passing through, occupancy rate, and queue length, etc. These raw data will be transmitted to a traffic data processing module, which will calculate the current vehicle density according to a preset algorithm, for example, based on the number of vehicles divided by the length of the road segment. Subsequently, the traffic data processing module compares the calculated vehicle density with the preset low-density state threshold value, for example, the preset low-density state can be defined as the vehicle density being lower than 10 vehicles per kilometer. If the currently calculated vehicle density is higher than the threshold value, the traffic data processing module will send an instruction to the signal control unit, instructing it to extend the red light duration of the main road direction signal light, for example, by 5 seconds each time. After receiving the instruction, the signal control unit will immediately update the red light duration and continue to maintain the red light state. This process will be executed in a loop, the traffic data processing module continuously obtains the updated vehicle density, and dynamically adjusts the red light duration according to the comparison result with the preset low-density state, until the vehicle density of the target road segment reaches or is lower than the preset low-density state. Once the low-density state is reached, the system considers that the traffic gap has been created, thereby preparing for subsequent emergency passage.

[0051] Optionally, in combination with Figure 7 As shown in S532, the step of obtaining the vehicle density of the road segment upstream of the target intersection includes: A1, obtaining vehicle presence information of the road segment upstream of the target intersection; A2, identifying non-moving vehicles and non-motor vehicles in the vehicle presence information of the road segment upstream of the target intersection; A3, excluding non-moving vehicles and non-motor vehicles in the vehicle presence information of the road segment upstream of the target intersection to obtain target intersection upstream vehicle presence information; A4, calculating the vehicle density of the road segment upstream of the target intersection according to the target intersection upstream vehicle presence information.

[0052] The vehicle presence information refers to a set of data describing the position, number or state of vehicles on a specific road segment, which can be obtained in various forms such as video images, radar signals, geomagnetic induction data or lidar point cloud data. The non-moving vehicle refers to a vehicle whose position or speed change does not reach a preset threshold within a certain time period, which can be determined by analyzing the continuous position data or speed data of the vehicle. The purpose is to distinguish between vehicles that are normally driving or temporarily parked and vehicles that are long-stopped or broken down. The non-motor vehicle refers to a vehicle that does not rely on engine or motor drive, but mainly relies on human or animal power, such as bicycles, electric bicycles or tricycles. It can be identified by the size, shape characteristics or movement pattern of the vehicle. The purpose is to exclude non-motor vehicles from motor vehicle statistics to obtain accurate motor vehicle traffic flow data.

[0053] In some preferred embodiments, obtaining the vehicle presence information of the road segment upstream of the target intersection can be specifically implemented by deploying video monitoring cameras and millimeter wave radars above the road segment. The video monitoring cameras can continuously capture real-time image or video data of the road segment, while the millimeter wave radars can provide speed, distance and angle information of the vehicles. Identifying non-moving vehicles and non-motor vehicles in the vehicle presence information of the road segment upstream of the target intersection can utilize image processing technology and machine learning models. For example, for video data, a target detection algorithm such as YOLO or Faster R-CNN can be used to identify the type (motor vehicle, bicycle, electric vehicle) and position of the vehicle in the image. At the same time, by analyzing the change of vehicle position between consecutive frames, combined with the speed data of the millimeter wave radar, it can be determined whether the vehicle is in a non-moving state. For example, if a vehicle's position changes less than a preset threshold within a certain number of seconds, or its speed is consistently close to zero, it can be identified as a non-moving vehicle. For non-motor vehicles, in addition to type identification, their typical movement patterns and speed ranges can also be used for auxiliary judgment. Excluding non-moving vehicles and non-motor vehicles from the vehicle presence information of the road segment upstream of the target intersection to obtain the vehicle presence information upstream of the target intersection can be done in the data processing unit by marking the data of the identified non-moving vehicles and non-motor vehicles as invalid or directly removing them from the statistical data set. For example, in the vehicle list, the identifiers of these vehicles are removed from the valid vehicle count, or in image analysis, only the areas identified as motor vehicles are processed subsequently. According to the vehicle presence information upstream of the target intersection, the vehicle density of the road segment upstream of the target intersection can be calculated by counting the number of motor vehicles on the target road segment within a certain time window and dividing it by the length of the road segment. For example, if the road segment length is L and the number of motor vehicles is N, the vehicle density can be calculated as N / L. This result will be used as the basis for determining whether the road segment reaches the preset low density state, thereby guiding the adjustment of the signal light.

[0054] Optionally, in combination with Figure 8 As shown, after the vehicles at the critical exit of the secondary road are released, the step of determining that the emergency situation is resolved and resuming the traffic signal control based on the preset initial signal includes: S81, obtaining the passing completion information of the vehicles at the critical exit of the secondary road; S82, determining that the emergency situation is resolved according to the passing completion information; S83, after the emergency situation is resolved, switching the signal control unit of the target intersection and the related intersection from the emergency mode to the initial mode; S84, loading the timing scheme corresponding to the preset initial signal to resume the traffic signal control.

[0055] Wherein, the passing completion information refers to the data for indicating whether the vehicles at the critical exit of the secondary road have completely passed through or left the exit area, which can be obtained by using the data of the number, speed, position or queue length of the vehicles monitored in real time by the vehicle detector (such as the geomagnetic sensor, video detector or radar sensor); the emergency situation resolved refers to the state that the system judges that the vehicles at the critical exit of the secondary road have safely passed through, and no longer needs special emergency traffic signal control, which can be logically judged based on the passing completion information, for example, when the vehicle density of the exit area is lower than the preset threshold or there is no vehicle retention; the emergency mode refers to a special running state of the traffic signal control unit when the critical exit is passively blocked, which can be manifested as that the signal timing scheme is temporarily adjusted to preferentially release the vehicles of the secondary road, or the traffic gap is manufactured for the main road, etc.; the initial mode refers to a conventional running state of the traffic signal control unit after the emergency situation is resolved, which can be manifested as that the control is performed according to the preset conventional signal timing scheme or the timing scheme adjusted based on the real-time traffic flow; the timing scheme corresponding to the preset initial signal refers to the parameter set of the cycle, phase, green ratio, etc. for guiding the switching of the traffic signal, which is pre-configured for a specific intersection or area under the normal running state of the traffic system, and can be formulated and stored according to the historical traffic data, road network structure or traffic management strategy.

[0056] In some preferred embodiments, the application is implemented as follows. After the vehicles at the critical exit of the secondary road are released, the traffic signal control system obtains the information of the completion of the vehicle passing through the area in real time through the video detector or geomagnetic sensor deployed at the critical exit of the secondary road. For example, the video detector can continuously analyze the image frames of the exit area, identify and track the moving track of the vehicle, and when it is detected that all the waiting vehicles have driven away from the exit area and no new vehicle enters the area within a certain time (for example, 5 seconds), the system can generate a passing completion signal. According to the passing completion information, the system determines that the emergency situation is over. Specifically, when the passing completion signal is received and it is confirmed that the vehicle density of the critical exit area has decreased to below the preset zero density threshold, the system triggers the determination of the emergency situation over. After the emergency situation is over, 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, so that these signal control units switch from the emergency mode to the initial mode. For example, a mode switching instruction package can be sent to each signal control unit through wired or wireless network communication protocol, which instructs the control unit to stop executing the current emergency timing logic and prepares to load the regular timing scheme. Subsequently, these signal control units load the timing scheme corresponding to the initial signal from their internal memory or central control server. For example, each signal control unit pre-stores multiple sets of regular timing schemes based on different time periods or traffic flow characteristics, and the system selects and loads the most suitable timing scheme according to the current time period (for example, the off-peak period) or real-time traffic flow data, for example, loads a regular timing scheme with a cycle of 120 seconds, a main road green light duration of 70 seconds, and a secondary road green light duration of 30 seconds, thereby restoring traffic signal control and returning the intersection traffic flow to normal management.

[0057] Optionally, in combination with Figure 9 As shown in FIG. 1, the step of S1 obtaining the main road traffic flow parameter of the main road and the secondary road exit vehicle existence information of the secondary road includes: S11, obtaining the original traffic data from various types of traffic sensors in the traffic accident area; S12, performing quality assessment on the original traffic data; S13, screening the sensor data according to the results of the quality assessment to obtain advanced sensor data; S14, fusing and verifying the advanced sensor data to generate final traffic data; S15, generating the main road traffic flow parameter of the main road and the secondary road exit vehicle existence information of the secondary road according to the final traffic data.

[0058] The various types of traffic sensors refer to different kinds of devices for collecting traffic information, such as geomagnetic sensors, radar sensors, video detectors, ultrasonic sensors, or floating car data collection devices, etc., aiming to provide multi-source heterogeneous traffic data. The raw traffic data refers to the initial data obtained directly from the various types of traffic sensors without any processing or preliminary processing, such as vehicle count, speed, occupancy rate, queue length, vehicle image, or GPS trajectory, etc., aiming to serve as the basis for subsequent data processing. The quality assessment refers to the process of checking and judging the integrity, accuracy, consistency, and timeliness of the raw traffic data, which can specifically include missing value detection, outlier identification, data format verification, or timestamp synchronization check, etc., aiming to identify and mark low-quality or unreliable data. The filtered sensor data refers to selecting a subset of data that meets the preset quality standards from the raw traffic data according to the results of the quality assessment, which can specifically be by setting a threshold to eliminate data marked as abnormal or incomplete, aiming to ensure that the data for subsequent processing has high reliability. The advanced sensor data refers to the sensor data that meets certain quality requirements and can be used for further processing after quality assessment and filtering, aiming to provide clean data input for data fusion and verification. The fusion and verification refer to the process of integrating data from different sensors or different types of data, and checking and correcting the integrated data for consistency, which can specifically use weighted average, Kalman filter, Bayesian network, or multi-sensor data association algorithm for data fusion, and through cross-validation, logical consistency check, or comparison with historical data for data verification, aiming to eliminate data redundancy, make up for data missing, and correct data bias, thereby generating more comprehensive, accurate, and robust traffic data.

[0059] In some preferred embodiments, the acquiring of the raw traffic data from various types of traffic sensors in the traffic accident area can specifically be: through the deployment of loop detectors, video monitoring cameras, radar sensors and accessed floating car GPS data in the traffic accident area and surrounding road sections, real-time collection of vehicle flow, speed, occupancy, queue length, vehicle image sequence and vehicle position information, etc. The quality assessment of the raw traffic data can specifically be: filling in missing values for loop data, for example, using adjacent time period or adjacent loop data for interpolation; image clarity assessment and abnormal frame detection for video data; signal-to-noise ratio analysis for radar data; and synchronization verification of the time stamps of all data, identifying and marking out data packet loss, sensor failure or obviously deviating from the normal range of abnormal values. According to the results of the quality assessment, the sensor data is filtered to obtain the advanced sensor data, which can specifically be: eliminating the data sources marked as low quality or abnormal, for example, if a certain loop continuously reports zero flow or abnormally high flow for more than a preset time, the data of the loop is temporarily disabled; if the video image is blurred, the video analysis result of the time period is not used. The fusion and verification of the advanced sensor data can specifically be: weighting and averaging fusion of the same type of data from different sensors, for example, the flow data detected by the loop and the video, the weight can be dynamically adjusted according to the historical reliability or real-time confidence of the sensor; at the same time, the vehicle speed data is smoothed by Kalman filtering algorithm, and logical verification is performed, for example, checking whether the vehicle flow and occupancy rate meet the basic traffic flow theory relationship, if not, it is modified. According to the final traffic data, the main road traffic flow parameters of the main road and the secondary road exit vehicle existence information of the secondary road can specifically be: based on the fused and verified data, the real-time flow, average speed and vehicle density of each lane of the main road are calculated as the main road traffic flow parameters; at the same time, by analyzing the vehicle identification results in the video image at the exit of the secondary road or the continuous occupancy signal of the loop, it is judged whether there is a vehicle staying at the exit for a long time, thereby generating the secondary road exit vehicle existence information.

[0060] A traffic accident surrounding traffic signal response system for performing traffic accident surrounding traffic signal response, comprising Figure 10 As shown in the figure, the traffic accident surrounding traffic signal response system 1 comprises: A parameter information acquisition module 11 for acquiring main road traffic flow parameters of a main road and secondary road exit vehicle existence information of a secondary road; A main road state judgment module 12 for judging whether the main road is in a main road congestion state according to the main road traffic flow parameters, to obtain a main road state judgment result; The secondary road state judgment module 13 is configured to judge whether the secondary road is in the secondary road exit abnormal stagnation state according to the secondary road exit vehicle existence information, and obtain a secondary road state judgment result. The blocked event identification module 14 is configured to identify and record as a key exit passive blocked event when the main road state judgment result and the secondary road state judgment result are both YES. The emergency response execution module 15 is configured to start an emergency response after recording the key exit passive blocked event, send a control instruction to the intersection upstream of the target intersection corresponding to the key exit passive blocked event, control the main road direction signal lamp of the intersection upstream of the target intersection to be red, and manufacture a traffic gap on the road segment upstream of the target intersection. The vehicle clearing execution module 16 is configured to turn the main road direction signal lamp of the target intersection to green after the traffic gap is manufactured, and clear the vehicles in the main road area in front of the key exit of the secondary road. The vehicle release execution module 17 is configured to release the vehicles of 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. The traffic signal recovery module 18 is configured to determine that the emergency situation is removed after the vehicles of the key exit of the secondary road are released, and recover the traffic signal control based on the preset initial signal.

[0061] The parameter information acquisition module is a unit for collecting and processing traffic data, which can be realized by connecting with various traffic sensors (such as ground coils, video detectors, radar sensors or floating car data interfaces), and its purpose is to provide basic data for subsequent traffic state judgment and emergency response. The main road state judgment module is a logic unit for analyzing main road traffic flow parameters to identify congestion conditions, which can be realized by real-time calculation and threshold comparison based on traffic flow density, speed, occupancy or queue length, etc., and its purpose is to identify the congestion of the main road and provide the basis for judging whether the key exit is passively blocked. The secondary road state judgment module is a logic unit for analyzing the existence information of secondary road exit vehicles to identify abnormal stagnation conditions, which can be realized by continuously monitoring the indicators such as the residence time of vehicles in the exit area, the number of vehicles or the queue length, and comparing them with the preset abnormal stagnation threshold, and its purpose is to identify the abnormal stagnation of the secondary road exit, combined with the main road state judgment result, to judge whether the key exit is passively blocked. The blocked event identification module is a decision unit for comprehensively judging the state of the main road and the secondary road to identify the key exit passive blocking event, which can be realized by receiving and logically judging the judgment results from the main road state judgment module and the secondary road state judgment module, and triggering event recording when both meet certain conditions, and its purpose is to identify the key traffic blocking event that needs special intervention as the trigger condition for starting emergency response. The emergency response execution module is a control unit for starting and coordinating traffic signal control to create a traffic gap after identifying the key exit passive blocking event, which can be realized by sending signal control instructions to the upstream intersection of the target intersection, making the signal light of the main road direction turn red, and thus forming a vehicle gap in a certain section, and its purpose is to create a passing space for the secondary road vehicle to drive in, avoiding passive waiting for the main road to naturally disperse. The vehicle emptying execution module is a control unit for clearing the vehicles in the main road area in front of the key exit of the secondary road after the formation of the traffic gap, which can be realized by making the signal light of the main road direction of the target intersection turn green, and adjusting the green light duration according to the actual emptying situation, and its purpose is to remove the obstacles in front of the key exit and provide physical convenience for the passing of the secondary road vehicles. The vehicle release execution module is a control unit for releasing the secondary road key exit vehicles after confirming that the main road area has been cleared, which can be realized by sending a passing instruction to the secondary road key exit after confirming that the clearing condition is met, and its purpose is to ensure that the secondary road vehicles can drive into the main road in a safe and sufficient space, avoiding long-term stagnation.The traffic signal recovery module is a control unit for restoring the traffic signal control to a normal or preset state after the emergency situation is handled, which can be implemented by determining that the emergency situation is resolved and loading a preset initial signal timing scheme after the vehicles on the secondary road are released, so as to avoid unnecessary long-term impact of the emergency response on other traffic flow and ensure the overall operation of the traffic system.

[0062] In some preferred embodiments, the application is implemented as follows. A traffic incident surrounding traffic signal response system can be deployed in a city traffic management center as a subsystem of an intelligent traffic management platform. A parameter information acquisition module can be a data acquisition and preprocessing unit that receives raw traffic data from loop inductance, video monitoring cameras, microwave radar, and floating car data platform in real time through wired or wireless network interface. The module performs preliminary cleaning, format conversion, and timestamp labeling on the received data to ensure data availability and consistency. The main road state judgment module and the secondary road state judgment module can be run as independent software services on the central processing server of the system. The main road state judgment module can output the main road congestion state by a preset congestion judgment algorithm (for example, when the speed is lower than a certain threshold and the lane occupancy rate is higher than a certain threshold, it is determined to be congested) according to the traffic main road traffic flow, average speed, and lane occupancy rate data provided by the parameter information acquisition module. The secondary road state judgment module can determine whether the secondary road is in an abnormal stagnation state according to the vehicle presence signal (for example, the loop inductance continuously triggers the signal or the video analysis recognizes the vehicle to be stationary for a long time) in the secondary road exit area combined with the vehicle queue length information. The blocked event recognition module can be an event trigger that continuously monitors the output of the main road state judgment module and the secondary road state judgment module. When both modules simultaneously send out "congestion" and "abnormal stagnation" signals, the module immediately recognizes and records it as a "key exit blocked event", and sends the event information to the emergency response execution module. The emergency response execution module can be a signal control instruction generation and sending unit that generates a signal control instruction for the upstream intersection of the target intersection after receiving the blocked event information. For example, the instruction can require the signal controller of the upstream intersection to immediately switch the signal light of the main road direction to red and keep it for a period of time to form a no-vehicle area, i.e. traffic gap, on the main road. The vehicle emptying execution module can be a dynamic signal adjustment unit that sends instructions to the target intersection to switch the signal light of the main road direction to green after the traffic gap is created. At the same time, the module continuously monitors the vehicle presence information in the main road area in front of the key exit of the secondary road, and if there are still vehicles in the area, it can prolong the green light duration until the area is cleared. The vehicle release execution module can be a traffic permission granting unit that sends instructions to the target intersection to switch the signal light of the key exit of the secondary road to green to allow the vehicles of the secondary road to enter the main road after confirming that the main road area in front of the key exit of the secondary road has been cleared. The traffic signal recovery module can be a mode switching and timing loading unit that receives the traffic completion signal after the vehicle release of the secondary road is completed to determine that the emergency situation is resolved.Subsequently, the module sends instructions to the signal controllers of the target intersection and the related intersections, so as to switch from the emergency mode back to the initial mode and load the preset initial signal timing scheme, thereby restoring the normal traffic signal control.

[0063] The above merely provides an example of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for responding to traffic signals in the vicinity of a traffic accident, characterized by, The method comprises the following steps: obtaining main road traffic flow parameters of a main road and secondary road exit vehicle existence information of a secondary road; judging whether the main road is in a main road congestion state according to the main road traffic flow parameters, and obtaining a main road state judgment result; judging whether the secondary road is in a secondary road exit abnormal stagnation state according to the secondary road exit vehicle existence information, and obtaining a secondary road state judgment result; when the main road state judgment result and the secondary road state judgment result both indicate yes, identifying and recording a key exit passive obstruction event; after recording the key exit passive obstruction event, starting an emergency response, sending a control instruction to an intersection upstream of a target intersection corresponding to the key exit passive obstruction event, and making the intersection upstream of the target intersection control a main road direction signal lamp to be red, so as to create a traffic gap on a road segment upstream of the target intersection; after the traffic gap is created, making the main road direction signal lamp of the target intersection turn to green, and emptying vehicles in a main road area in front of a 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 emptied, releasing the vehicles of the key exit of the secondary road; after releasing the vehicles of the key exit of the secondary road, determining that the emergency situation is over and restoring traffic signal control based on a preset initial signal.

2. The method of claim 1, wherein, The step of starting an emergency response after recording the key exit passive obstruction event, sending a control instruction to an intersection upstream of a target intersection corresponding to the key exit passive obstruction event, and making the intersection upstream of the target intersection control a main road direction signal lamp to be red, so as to create a traffic gap on a road segment upstream of the target intersection, comprises the following steps: sending an emergency silence instruction to the intersection upstream of the target intersection corresponding to the key exit passive obstruction event; the emergency silence instruction makes a signal control unit of the intersection upstream of the target intersection enter an emergency silence state; after entering the emergency silence state, the signal control unit suspends responding to a vehicle detector input signal related to a road segment upstream of the target intersection, and locks the signal lamp leading to the target road segment to be red, so as to create a traffic gap on the road segment upstream of the target intersection.

3. The method of claim 1, wherein, The step of emptying vehicles in a main road area in front of a key exit of a secondary road comprises the following steps: making a main road direction signal lamp of a target intersection turn to green; obtaining vehicle existence information of the main road area in front of the key exit of the secondary road; determining an emptying state of the main road area in front of the key exit of the secondary road according to the vehicle existence information; when the emptying state does not reach a preset emptying condition, prolonging a green light duration of the main road direction signal lamp of the target intersection until the emptying state reaches the preset emptying condition; after the emptying state reaches the preset emptying condition, continuously obtaining subsequent vehicle existence information of the main road area in front of the key exit of the secondary road; when the subsequent vehicle existence information shows that the main road area in front of the key exit of the secondary road has vehicles entering again, prolonging the green light duration of the main road direction signal lamp of the target intersection again.

4. The method of claim 3, wherein, The step of determining the emptying state of the main road area in front of the key exit of the secondary road according to the vehicle existence information comprises the following steps: According to the vehicle presence information, an actual empty space of a main road area in front of a key exit of a secondary road is obtained; Size information of a vehicle waiting at the key exit of the secondary road is obtained; According to the size information, a required minimum empty space of the main road area in front of the key exit of the secondary road is determined; The actual empty space is compared with the required minimum empty space to determine the empty state of the main road area in front of the key exit of the secondary road.

5. The method of claim 1, wherein, The step of releasing the vehicle 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 is empty includes: After confirming that the main road area in front of the key exit of the secondary road is empty, traffic flow state information of a road section downstream of the key exit of the secondary road is obtained; According to the traffic flow state information, the traffic capacity of the road section downstream of the key exit of the secondary road is determined; If the traffic capacity is less than a preset traffic capacity threshold, the vehicle at the key exit of the secondary road is delayed to be released; If the traffic capacity is greater than or equal to the preset traffic capacity threshold, the vehicle at the key exit of the secondary road is released.

6. The method of claim 2, wherein, The step of creating a traffic gap in a road section upstream of a target intersection includes: Controlling the red light duration of an intersection main road direction signal lamp of the road section upstream of the target intersection; Obtaining the vehicle density of the road section upstream of the target intersection; Determining whether the vehicle density reaches a preset low density state; When the vehicle density does not reach the preset low density state, the red light duration of the intersection main road direction signal lamp of the road section 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.

7. The method of claim 6, wherein, The step of obtaining the vehicle density of the road section upstream of the target intersection includes: Obtaining vehicle presence information of the road section upstream of the target intersection; Identifying non-moving vehicles and non-motor vehicles in the vehicle presence information of the road section upstream of the target intersection; Excluding the non-moving vehicles and the non-motor vehicles in the vehicle presence information of the road section upstream of the target intersection to obtain target intersection upstream vehicle presence information; According to the target intersection upstream vehicle presence information, the vehicle density of the road section upstream of the target intersection is calculated.

8. The method of claim 1, wherein, The step of determining that the emergency situation is resolved and restoring the traffic signal control based on a preset initial signal after the vehicle at the key exit of the secondary road is released includes: Obtaining traffic completion information of the vehicle at the key exit of the secondary road; According to the traffic completion information, it is determined that the emergency situation is resolved; After the emergency situation is resolved, the signal control unit of the target intersection and related intersections is switched from the emergency mode to the initial mode; A timing scheme corresponding to the preset initial signal is loaded to restore the traffic signal control.

9. The method of claim 1, wherein, The step of obtaining the main road traffic flow parameter of the traffic main road and the secondary road exit vehicle presence information of the traffic secondary road includes: Obtaining original traffic data from various types of traffic sensors in the traffic accident area; Quality evaluation is performed on the original traffic data; According to the results of the quality evaluation, sensor data is screened to obtain advanced sensor data; The advanced sensor data is fused and verified to generate final traffic data; According to the final traffic data, a main road traffic flow parameter of a main road and exit vehicle existence information of a secondary road are generated.

10. A traffic signal response system for a traffic accident, used to respond to traffic signals around a traffic accident, characterized in that: The method comprises the following steps: a parameter information acquisition module is configured to acquire the main road traffic flow parameter of the main road and the exit vehicle existence information of the secondary road; a main road state judgment module is configured to judge whether the main road is in a main road congestion state according to the main road traffic flow parameter, and obtain a main road state judgment result; a secondary road state judgment module is configured to judge whether the secondary road is in a secondary road exit abnormal stagnation state according to the exit vehicle existence information of the secondary road, and obtain a secondary road state judgment result; a blocked event identification module is configured to identify and record a key exit passive blocked event when the main road state judgment result and the secondary road state judgment result are both YES; an emergency response execution module is configured to start an emergency response after the key exit passive blocked event is recorded, send a control instruction to an intersection upstream of a target intersection corresponding to the key exit passive blocked event, and control a main road direction signal lamp of the intersection upstream of the target intersection to be red to create a traffic gap on a road segment upstream of the target intersection; a vehicle emptying execution module is configured to turn the main road direction signal lamp of the target intersection to green and empty vehicles in a main road area in front of a key exit of the secondary road after the traffic gap is created; a vehicle release execution module is configured to release vehicles of 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 emptied; a traffic signal recovery module is configured to determine that the emergency situation is over and recover the traffic signal control based on a preset initial signal after the vehicles of the key exit of the secondary road are released.

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