Dynamic expansion control method for highway accident congestion based on ETC door frame

Abstract

The invention discloses a dynamic expansion management and control method for highway accident congestion based on an ETC portal, and relates to the technical field of traffic management and control, and the method comprises the steps: obtaining accident information; calculating the queuing length of the accident scene; the congestion duration is predicted, wherein the congestion duration is composed of rescue time, obstacle clearing time and congestion dissipation time; dilatation management and control are carried out in different areas, a control area and a buffer area are sequentially divided from the accident occurrence place along the rear, and dynamic dilatation management and control are carried out according to the actual traffic capacity of the accident road section. The method has remarkable advantages in the aspects of quick response, resource adjustment, timely rescue, accurate prediction, plan making and the like, decision scientificity is improved, effectiveness of active traffic management is improved, management strategies of active traffic management are refined, scientificity and rationality of dynamic management and control measures are improved, and the method is suitable for popularization and application. The method is of great significance in improving the emergency processing capacity of the expressway and guaranteeing traffic safety and smoothness.

Description

Technical Field

[0001] The present invention relates to the technical field of traffic control, and in particular to a dynamic capacity expansion control method for highway accidents and congestion based on ETC gantries. Background Art

[0002] At present, the video surveillance coverage rate of domestic highways is 100%, with full-course monitoring, full-time detection, and full-area coverage; LED display screens are installed in all service areas, toll stations, large bridges, extra-large bridges, tunnels with medium spans and above, tunnel groups, interchange ramps, ramp entrances, diversion areas, etc.; the installation of ETC gantries not only realizes non-stop automatic toll collection but also provides support for accurate perception of highway traffic flow. Highway outfield perception devices can meet the intelligent and refined control requirements of highways in terms of coverage rate, layout density, and device types.

[0003] Highways have high speeds and large traffic volumes. After a traffic accident occurs, traffic flow will accumulate in a short time, causing congestion. If not handled properly, secondary accidents will be triggered, exacerbating the impact and losses of the accident. Therefore, how to perform dynamic capacity expansion control for traffic congestion caused by sudden accidents is an urgent problem to be solved. Summary of the Invention

[0004] In order to overcome the above defects in the prior art, the present invention provides a dynamic capacity expansion control method for highway accidents and congestion based on ETC gantries, which pre-judges and controls the possible impact range of the accident in zones, and combines the use of oncoming lanes, emergency lanes, speed limits, and precise guidance to expand the capacity of the accident section and improve the traffic capacity.

[0005] To achieve the above object, the present invention adopts the following technical solutions, including: A dynamic capacity expansion control method for highway accidents and congestion based on ETC gantries, comprising the following steps: S1, obtaining accident information, including the accident occurrence time, accident location, accident-occupied lane, and accident vehicles; S2, calculating the queue length at the accident site; S3, predicting the congestion duration T, where the congestion duration consists of the rescue time T1, the breakdown clearance time T2, and the congestion dissipation time T3, and T = T1 + T2 + T3; S4, performing capacity expansion control in zones. According to the congestion duration, the area is divided, and starting from the accident location, the rear along the forward direction of the road is successively divided into a control area and a buffer area. The actual traffic capacity C of the accident section is judged, and capacity expansion control is performed: If C≠0 and the cross-sectional traffic volume Q1 of the upstream section < C, then dynamic speed limit is enabled for the control area, and no measures are taken for the buffer area; If C≠0 and the cross-sectional traffic volume Q1 of the upstream section ≥ C, the emergency lane is enabled for the control area; at the same time, vehicles in the buffer area are prompted that there is an accident section ahead. If C = 0, the oncoming lane is enabled for the control area, and at the same time, vehicles in the buffer area are restricted from entering the control area.

[0006] Preferably, the length L of the control area c is: ; where L is the queue length at the accident scene, Q2 is the cross-sectional traffic volume of the accident section, K2 is the traffic flow density of the accident section, Q1 is the cross-sectional traffic volume of the upstream section, and K1 is the traffic flow density of the upstream section.

[0007] Preferably, the length L of the buffer area b is: ; where is the average driving speed of vehicles in the upstream section, and T is the duration of congestion.

[0008] Preferably, in step S4, according to the number of lanes occupied by the accident and the traffic flow density K2 of the accident section, dynamic speed limit is enabled for the control area, specifically as follows: If the accident does not occupy a lane, judge the magnitude of the traffic flow density K2 of the accident section: if K2 < A1, the maximum driving speed of the control area is restricted to VA1; if A1 ≤ K2 < A2, the maximum driving speed of the control area is restricted to VA2; if A2 ≤ K2, the maximum driving speed of the control area is restricted to VA3; where A1, A2 are set thresholds, VA3, VA2, VA1 are set driving speeds, A1 < A2, VA3 < VA2 < VA1; If the accident occupies 1 lane, judge the magnitude of the traffic flow density K2 of the accident section: if K2 < B1, the maximum driving speed of the control area is restricted to VB1; if B1 ≤ K2 < B2, the maximum driving speed of the control area is restricted to VB2; if B2 ≤ K2, the maximum driving speed of the control area is restricted to VB3; where B1, B2 are set thresholds, VB3, VB2, VB1 are set driving speeds, B1 < B2, VB3 < VB2 < VB1; If an accident occupies two or more lanes, then determine the magnitude of the traffic flow density K2 of the accident section: If K2 < C1, then limit the maximum driving speed of the control area to VC1; If C1 ≤ K2 < C2, then limit the maximum driving speed of the control area to VC2; If C2 ≤ K2, then limit the maximum driving speed of the control area to VC3; where C1 and C2 are set thresholds, VC3, VC2, and VC1 are set driving speeds, C1 < C2, and VC3 < VC2 < VC1; Among them, C1 < C2 ≤ B1 < B2 ≤ A1 < A2, VC3 < VB3 < VA3, VC2 < VB2 < VA2, VC1 < VB1 < VA1.

[0009] Preferably, in step S2, based on the video monitoring of the ETC gantries on the highway, calculate the queuing length L at the accident site, specifically as follows: Collect the video images of the ETC gantry at the accident location, that is, the first ETC gantry, and perform target recognition on the images to obtain the queuing length L1 within the monitoring range of the first ECT gantry; Collect the video images of each ETC gantry behind the accident location to obtain the queuing length L within the monitoring range of the jth ECT gantry j ; j = 2, 3,...; The maximum value of the monitoring range of the ETC gantry is L limit , if L1 < L limit , then the queuing length L at the accident site = L1; if L1 = L limit , then search sequentially for the ETC gantry behind until L j < L limit is found, and L j-1 = L limit , then the queuing length L at the accident site = d 1，j + L j ; where d 1，j is the distance between the first ETC gantry and the jth ETC gantry.

[0010] Preferably, in step S3, the rescue time T1 is the time required for the rescue vehicle to reach the accident location, and the calculation method of the rescue time T1 is: Obtain the location information of the accident location; According to the GPS location information of all rescue vehicles, match the rescue vehicle closest to the accident location; According to the location information of the accident location and the location information of the rescue vehicle, use the path planning algorithm to plan the path with the shortest time required for the rescue vehicle to reach the accident location; According to the real-time traffic flow information of the accident section, predict the driving time of the rescue vehicle from the nearest toll station entrance to the accident location; The rescue time T1 is obtained by adding the travel time of the rescue vehicle from the nearest toll station entrance to the accident site to the normal time for the rescue vehicle to arrive at the nearest toll station entrance.

[0011] Preferably, in step S3, the obstacle clearance time T2 is the time required to clear the accident obstacle on the road, and the obstacle clearance time T2 is calculated as follows: Collect historical clearance times for various accident types and construct datasets for different accident types; For the accident whose clearance time T2 is to be calculated, determine the accident type, select the corresponding data set according to the accident type, and select the median of the historical clearance time in the data set as the clearance time T2.

[0012] Preferably, in step S3, the congestion dissipation time T3 is calculated based on the cross-sectional traffic volume Q2 and the vehicle flow density K2 of the accident section, the cross-sectional traffic volume Q1 and the vehicle flow density K1 of the upstream section, and the cross-sectional traffic volume Q3 and the vehicle flow density K3 of the downstream section: ; Among them, the upstream section refers to the section behind the accident section along the direction of the road; the downstream section refers to the section in front of the accident section along the direction of the road; L is the queue length at the accident scene.

[0013] Preferably, by retrieving the ETC gantries corresponding to the accident section, the upstream section and the downstream section, the cross-sectional traffic volume of each section is obtained based on the cross-sectional traffic volume within the monitoring range of each ETC gantries; wherein the cross-sectional traffic volume within the monitoring range of the i-th ETC gantry is: ; Among them, Q id is the cross-section traffic volume within the monitoring range of the i-th ETC gantry, in units of pcu / h. The cross-section traffic volume refers to the number of vehicles passing through the road section within 1 hour, which is converted into standard vehicles for counting; k n is the conversion factor of the nth model, Q ind is the cross-sectional traffic volume of the nth vehicle type within the monitoring range of the i-th ETC gantry; By retrieving the ETC gantries corresponding to the accident section, upstream section and downstream section, the traffic density of each section is obtained based on the traffic density within the monitoring range of each ETC gantries; among which, the traffic density within the monitoring range of the i-th ETC gantry is: K id =H / h sid ; Among them, K id is the traffic density within the monitoring range of the ith ETC gantry. The traffic density refers to the number of vehicles within the monitoring range of the ETC gantry.sid is the headway distance within the monitoring range of the i-th ETC gantry; H is the road length within the monitoring range of the ETC gantry.

[0014] Preferably, it is characterized in that, in step S4, the actual traffic capacity C of the accident section is calculated as follows: C=K×Q; where Q is the design capacity of the accident section on the highway; and K is the reduction factor.

[0015] The advantages of the present invention are: (1) The present invention provides a dynamic expansion control method for highway accident congestion based on an ETC gantry. By collecting data through existing equipment on the highway, sudden accidents are discovered in a timely manner, and the possible impact range of the accident is pre-judged and controlled by zoning. The oncoming lane, emergency lane, speed limit, and precise guidance are combined to expand the capacity of the accident section, improve the traffic capacity, slow down the speed of congestion, improve the safety of the accident-affected section, save travelers' congestion time, and improve travel comfort.

[0016] (2) The present invention provides a dynamic expansion control method for highway accident congestion based on the ETC gantry, which can quickly adjust road resources after an accident occurs, increase road traffic resources in a targeted manner, carry out rescue and obstacle removal as soon as possible, accurately predict the time, and provide emergency response plans, saving response time and reducing delay losses caused by accidents.

[0017] (3) The present invention conducts control by region, monitors traffic flow, vehicle speed, traffic accidents and other data in real time, predicts the impact range and possibility of traffic congestion, formulates targeted capacity expansion control based on the characteristics of the road network structure and the different degrees of impact of traffic congestion, organizes and dispatches traffic flow, thereby improving the road's traffic capacity and strengthening accident handling and road recovery capabilities.

[0018] (4) The dynamic speed limit strategy in regional expansion control can adjust the speed limit values ​​in different areas according to the real-time traffic conditions and road characteristics. The main purpose is to actively intervene and reduce the possibility of increased congestion and secondary accidents. The dynamic speed limit combined with real-time traffic flow can better balance the road network load, reduce the risk of short-term traffic congestion on accident sections, and evenly distribute traffic in the buffer area, reducing interference with the control area.

[0019] (5) The present invention follows the traffic engineering theory and scientifically and reasonably sets the control facilities to ensure that the driver can understand them and realize perception, management, induction interaction and coordination. The dynamic speed limit value is reasonably determined to avoid excessive speed difference between adjacent sections, low speed in congested sections, and high speed in buffer areas. Speed ​​difference control is done in advance to avoid a significant reduction that affects driving comfort, or even causes traffic safety hazards or secondary accidents.

[0020] (6) After an accident occurs, the method of the present invention quickly identifies the congested area and adjusts road resources in a targeted manner, including reallocating lanes, dynamically limiting speeds, activating emergency lanes, etc., to maximize road capacity.

[0021] (7) The present invention is different from the traditional fixed road configuration. The present invention can increase road traffic resources in a targeted manner according to the specific circumstances of the accident, such as the severity of the accident, the degree of congestion, etc. This may include temporarily opening emergency lanes, adding temporary traffic signs and signals, etc., to quickly alleviate congestion.

[0022] (8) The present invention can carry out rescue and obstacle removal work in the first place through the dynamic expansion control method, including fast-response rescue vehicles, emergency medical services and road obstacle removal equipment, to ensure that the injured receive timely treatment and restore normal traffic on the road as soon as possible.

[0023] (9) The present invention utilizes advanced data analysis technology, combined with historical data and real-time data, to accurately predict the time required for accident handling, which helps to formulate emergency response plans in advance and ensure the orderly progress of various tasks.

[0024] (10) Based on accurate time prediction, the present invention can provide a detailed plan for emergency response, including personnel deployment, material preparation, traffic diversion and other aspects, to ensure that the accident can be handled quickly and effectively after it occurs.

[0025] (11) Through dynamic capacity expansion control methods and accurate time prediction, the present invention can significantly save the time for accident handling, which can not only reduce traffic congestion and delays caused by accidents, but also reduce the economic losses and social impacts caused by them.

[0026] (12) The method for dynamic expansion control of highway accident congestion provided by the present invention has significant advantages in rapid response, resource adjustment, timely rescue, accurate prediction and plan formulation, and is of great significance for improving the emergency response capability of highways and ensuring traffic safety and smoothness. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The figure is a flow chart of the dynamic expansion control method for highway accident congestion based on ETC gantries.

[0028] Figure 2 Schematic diagram of the division of control area and buffer area.

[0029] Figure 3 This is a diagram of the dynamic expansion management and control strategy for the control area.

[0030] Figure 4 This is a diagram of the dynamic expansion control strategy for the buffer area.

[0031] Figure 5 This is a dynamic speed limit control strategy diagram for the control area. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Depend on Figure 1 As shown, the present invention provides a dynamic expansion control method for highway accident congestion based on an ETC gantry, comprising the following steps: S1, obtain accident information.

[0034] Use video surveillance equipment on highways (including highway roadside video surveillance and ETC gantry video surveillance) to detect accidents and obtain accident information, including the time of the accident, the location of the accident, the lane occupied by the accident, the accident vehicle, etc.

[0035] After the accident is detected, the accident information is automatically reported. In this embodiment, after the staff obtains the accident information, they verify the authenticity and accuracy of the accident information through video inspection, and verify, confirm and improve the automatically reported accident information. Since the accident detection algorithm of video surveillance itself has certain errors, in addition, due to the long-term use of field video surveillance equipment, there are problems such as lack of maintenance and lens occlusion, which will also reduce the accuracy of accident detection. In order to improve the accuracy of accident detection, this embodiment also adds manual inspections for confirmation and review. At the same time, the staff can also synchronize the accident information to highway management, traffic police, related rescue and other departments as soon as possible.

[0036] S2, calculate the queue length L at the accident scene.

[0037] Since the installation angle of the ETC gantry faces the highway road surface, the video surveillance of the ETC gantry is used to obtain the queue length at the accident scene. The queue length is calculated based on the video image with high accuracy and calibration precision.

[0038] The calculation process of the queue length L at the accident scene is as follows: S21, collecting the video image of the ETC gantry where the accident occurred, i.e., the first ETC gantry, performing target recognition on the image, and obtaining the queue length L1 within the monitoring range of the first ECT gantry.

[0039] S22, collect video images of each ETC gantries behind the accident site, and obtain the queue length L within the monitoring range of the jth ECT gantry j ; j=2,3,... .

[0040] S23, the maximum value of the ETC gantry monitoring range is L limit , if L1 <L limit , then the queue length at the accident site is L=L1; if L1=L limit , then search the ETC gantry in the rear until L is found. j <L limit , and L j-1 =L limit , then the queue length at the accident site is L=d 1，j +L j ; where d 1，j is the distance between the 1st ETC gantry and the jth ETC gantry.

[0041] Among them, d 1，j The distance between the two ETC gantries can be calculated based on the stake numbers of the two ETC gantries, or based on the longitude and latitude information of the two ETC gantries. In this embodiment, the longitude and latitude information of the two ETC gantries is used to calculate the distance between the two ETC gantries, which is more applicable.

[0042] S3, predict congestion duration T.

[0043] The congestion duration T is composed of the rescue time T1, the obstacle clearance time T2, and the congestion elimination time T3: T=T1+T2+T3.

[0044] The rescue time T1 is the time required for the rescue vehicle to arrive at the accident site. In this embodiment, the time required for the rescue vehicle to arrive at the nearest toll station entrance is calculated according to the regular time. The rescue vehicle arrives at the nearest toll station entrance in 10-15 minutes during the day and 15-20 minutes at night. At present, all rescue vehicles have GPS positioning devices, and the management and control platform integrates the GPS location information of all rescue vehicles. It can automatically match the nearest rescue vehicle through the location information of the accident site, and plan the fastest route for the rescue vehicle to reach the accident site. The accident rescue time T1 is predicted based on the real-time traffic flow information of the accident section and the regular time to arrive at the nearest toll station entrance.

[0045] The rescue time T1 is calculated as follows: S311, when an accident occurs, obtain the location information of the accident site, that is, the longitude and latitude information.

[0046] S312, using the GPS location information of all rescue vehicles integrated in the management and control platform, automatically matches the rescue vehicle closest to the accident site.

[0047] S313, based on the accident site and the current location of the rescue vehicle, a map service or a path planning algorithm (such as Dijkstra, A*, etc.) is used to plan a path with the shortest time required for the rescue vehicle to reach the accident site, and the distance of the planned path is obtained.

[0048] S314, predicting the travel time of the rescue vehicle from the nearest toll station entrance to the accident site based on the real-time traffic flow information of the accident section (such as congestion, road closure, etc.). Real-time traffic flow information can be obtained through traffic monitoring cameras, sensors, GPS data of other vehicles, etc. There are emergency lanes on the highway for rescue, and rescue can use the opposite lane. In this embodiment, the predicted travel time is the distance of the planned path / the speed of the rescue vehicle.

[0049] S315, the predicted travel time of the rescue vehicle from the nearest toll station entrance to the accident site is added to the regular time (fixed time, i.e. 10-15 minutes during the day and 15-20 minutes at night) of the rescue vehicle arriving at the nearest toll station entrance to obtain the rescue time T1.

[0050] The obstacle clearance time T2 is the time required to clear the accident obstacle on the road. The obstacle clearance time T2 is analyzed based on historical obstacle clearance data. According to the obstacle clearance time corresponding to different accident types, the median is directly selected through the median function in similar accident types. In this embodiment, the accident types are divided into minor, general, major, and extremely major. The accident type is determined according to the provisions of the "Notice on the Classification Standards of Road Traffic Accidents".

[0051] The calculation method of obstacle clearance time T2 is: S321, collect historical towing data under various accident types; check the integrity of historical towing data to ensure that there are no missing values ​​or outliers. If there are missing values ​​or outliers, process them according to the situation, such as deletion, interpolation or replacement; divide the historical towing data into four subsets according to the accident type, namely minor, general, major and extremely large, to construct data sets of different accident types.

[0052] Among them, historical clearance data includes historical clearance time, time of occurrence, and accident type.

[0053] S322, for the accident for which the clearance time T2 is to be calculated, determine the accident type according to the provisions of the "Notice on the Classification Standards for Road Traffic Accidents", select the corresponding data set according to the accident type, use the median function to calculate the median of the historical clearance time in the data set, and use it as the clearance time T2.

[0054] The prediction of congestion dissipation time T3 is calculated based on the cross-sectional traffic volume Q2 and traffic density K2 of the accident section, the cross-sectional traffic volume Q1 and traffic density K1 of the upstream section, and the cross-sectional traffic volume Q3 and traffic density K3 of the downstream section.

[0055] Among them, cross-sectional traffic volume refers to the number of vehicles passing through the cross-section of a road. Cross-sectional traffic volume is usually counted in hours and can be obtained through traffic flow surveys, traffic monitoring equipment or traffic models. By measuring cross-sectional traffic volume, we can understand the busyness of the road section, traffic congestion and changing trends in traffic flow, thereby providing a basis for traffic planning, road design and traffic management.

[0056] Vehicle density, also known as traffic flow density, is the number of vehicles at a certain moment on a road section with a unit length of 1 km. It is used to indicate the density of vehicles on the road section.

[0057] The calculation method of the predicted congestion dissipation time T3 is: S331, based on the cross-sectional traffic volume within the monitoring range of each ETC gantry on the expressway, obtain the cross-sectional traffic volume of the road section; ; Among them, Q id is the cross-section traffic volume within the monitoring range of the i-th ETC gantry, and the unit is pcu / h. The cross-section traffic volume refers to the number of vehicles passing through the road section within 1 hour, which is converted into standard vehicles for counting; k n is the conversion coefficient of the nth model, which is a constant value; Q ind It is the cross-sectional traffic volume of the nth vehicle type within the monitoring range of the i-th ETC gantry.

[0058] There is a correlation between the ETC gantry and the road section. By retrieving the ID number of the ETC gantry corresponding to the upstream section, accident section and downstream section, the cross-sectional traffic volume of each section can be obtained.

[0059] S332, based on the video surveillance of each ETC gantries on the highway, obtains the headway distance between two adjacent vehicles according to the video image, and calculates the traffic density of the road section: K id =1000 / h sid ; Among them, K id is the traffic density within the monitoring range of the ith ETC gantry. The traffic density refers to the number of vehicles on a road with a unit length of 1 km at a certain moment; h sid is the headway distance between vehicles within the monitoring range of the i-th ETC gantry, specifically, the average headway distance between all adjacent vehicles in the video image.

[0060] There is a correlation between the ETC gantry and the road section. By retrieving the ID number of the ETC gantry corresponding to the upstream section, accident section, and downstream section, the traffic density of each section can be obtained.

[0061] S333, congestion dissipation time T3 is: ; Among them, the upstream section refers to the section behind the accident section along the direction of road advancement; the downstream section refers to the section in front of the accident section along the direction of road advancement; L is the queue length at the accident scene; Q1 is the cross-sectional traffic volume of the upstream section; K1 is the traffic density of the upstream section; Q2 is the cross-sectional traffic volume of the accident section; K2 is the traffic density of the accident section; Q3 is the cross-sectional traffic volume of the downstream section; K3 is the traffic density of the downstream section; T1 is the rescue time; T2 is the obstacle clearance time.

[0062] S4, expand capacity and control in different areas to improve the traffic capacity of accident sections and reduce congestion length and delays. Figure 2 As shown, starting from the accident site, the rear is divided into a control area and a buffer area.

[0063] The control area refers to: after an accident occurs, the area covered by the queue length directly caused by the accident, and the area aggravated by the congestion caused by the continuous entry of vehicles during the duration of congestion caused by the accident (including rescue, clearance and dissipation time), collectively referred to as the control area.

[0064] The control area has the following characteristics: 1. The control area will be directly affected by the accident, and the speed of vehicles will be significantly reduced or even completely stopped. 2. The length and scope of the control area will change with the progress of the accident handling (such as rescue, obstacle removal and dissipation) and changes in traffic flow.

[0065] The control area is the management focus. The traffic management department needs to focus on the control area to ensure that rescue vehicles and personnel can arrive at the scene quickly, and at the same time take measures to reduce the impact of the accident on traffic flow.

[0066] The buffer area refers to: after an accident occurs, in order to ensure that traffic congestion in the control area can be effectively dissipated, before the traffic flow returns to normal, it is necessary to guide and manage vehicles that may enter the control area in advance. This area is called the buffer area.

[0067] The buffer area has the following characteristics: although the buffer area is not directly affected by traffic accidents, its traffic flow may be affected by congestion in the control area.

[0068] Traffic management departments need to set up warning signs, induction signs or take other measures in the buffer area to guide vehicles to detour or slow down in advance to reduce traffic pressure in the control area.

[0069] Generally speaking, both the control area and the buffer area play important roles in traffic incident management. The control area is the area directly affected by the accident, focusing on key attention and emergency handling; the buffer area is a warning and induction area set to relieve the pressure on the control area and ensure that the traffic flow can return to normal as soon as possible.

[0070] In the present invention, the length L of the control area c is: ; The length L of the buffer area b is: ; wherein, T is the congestion duration; is the average driving speed of vehicles on the upstream section. By using the video monitoring of the ETC gantries on the upstream section and obtaining the driving speeds of all vehicles based on the video images within the statistical period, the average driving speed of vehicles on the upstream section can be obtained.

[0071] The management and control strategy of the control area is: according to the relationship between the traffic flow of the accident section and the traffic flow of the upstream section, as well as the traffic capacity of the accident section, determine whether to activate the oncoming lane, whether to enable the emergency lane, whether to enable dynamic speed limit, and link the induction screen. When the emergency lane is enabled, stop the illegal function of the emergency lane and activate the functions of lane-changing across the solid line and illegal parking in the emergency lane.

[0072] The range of the buffer area may be a linear route or may be the connected sections affected by the spread through the interchange, which is the area where vehicles may reach the control area before the congestion dissipates, that is, the indirectly affected area. The management and control strategy of the buffer area is: issue instructions to the induction screen, checkpoint, speed limit signboard, etc. that need to be controlled.

[0073] In the present invention, as shown by Figure 3 and Figure 4 , the capacity expansion management and control by region is specifically as follows: S41, judge the actual traffic capacity C of the accident section: if C≠0 and the cross-sectional traffic volume Q1 of the upstream section < C, then enter step S42; if C≠0 and the cross-sectional traffic volume Q1 of the upstream section ≥ C, then enter step S43; if C = 0, then enter step S44.

[0074] S42, enable dynamic speed limit for the control area and take no measures for the buffer area at the same time.

[0075] Among them, as shown by Figure 5 , the specific dynamic speed limit method of the control area is as follows: S421, determine the number of lanes occupied by the accident: if the accident does not occupy any lanes, proceed to step S422; if the accident occupies one lane, proceed to step S423; if the accident occupies two or more lanes, proceed to step S424; in this embodiment, take three one-way lanes as an example.

[0076] S422, determine the size of the traffic density K2 of the accident section: if K2<50, the maximum driving speed in the restricted control area is 100km / h; if 50≤K2<65, the maximum driving speed in the restricted control area is 80km / h; if 65≤K2, the maximum driving speed in the restricted control area is 60km / h.

[0077] S423, determine the size of the traffic density K2 of the accident section: if K2<35, the maximum driving speed in the restricted control area is 80km / h; if 35≤K2<50, the maximum driving speed in the restricted control area is 60km / h; if 50≤K2, the maximum driving speed in the restricted control area is 40km / h.

[0078] S424, determine the size of the traffic density K2 of the accident section: if K2<20, the maximum driving speed in the restricted control area is 60km / h; if 20≤K2<35, the maximum driving speed in the restricted control area is 40km / h; if 35≤K2, the maximum driving speed in the restricted control area is 20km / h.

[0079] S43, the emergency lane is activated in the control area, and the induction screen in the control area is used to prompt that the emergency lane is open. When the emergency lane is activated, the emergency lane violation function is stopped, and the emergency lane solid line lane change and illegal parking functions are activated. At the same time, the vehicles in the buffer area are prompted, and the induction screen in the buffer area is used to prompt that there is an accident section ahead, please drive carefully, and the speed limit of the control area ahead, that is, the maximum driving speed, is prompted.

[0080] S44, activate the opposite lane in the control area, and use the guidance screen in the control area to prompt vehicles to use the opposite lane, and organize and guide traffic in the opposite lane; at the same time, restrict vehicles in the buffer area from entering the control area, and use the guidance screen in the buffer area to prompt vehicles that there is a severely congested accident section ahead, please take a detour.

[0081] The calculation of the actual capacity C of the accident section involves multiple factors, which is mainly based on the design capacity of the road and adjusted according to the specific circumstances of the accident. The design capacity is the actual acceptable capacity of the road. It is calculated based on the basic capacity of a single lane (usually in pcu / h), the number of one-way lanes, the lane width and lateral clear width correction factor, the large vehicle correction factor, and the driver condition correction factor. When a traffic accident occurs, the design capacity of the road will be affected, and the remaining capacity, that is, the actual capacity C, needs to be calculated based on the specific circumstances of the accident. The remaining capacity is usually calculated by multiplying the design capacity by a reduction factor K, which reflects the degree of impact of the accident on the road capacity. The specific value of the reduction factor K needs to be determined based on factors such as the severity of the accident (i.e., the type of accident), the number of occupied lanes, and the expected duration of congestion.

[0082] In this embodiment, the reduction coefficient K is adjusted based on the number of lanes occupied by the accident. The more lanes occupied by the accident, the greater the impact on the traffic capacity, and the smaller the reduction coefficient K. Based on the "Road Capacity Manual", the traffic capacity of the accident section is fixedly reduced, and three corresponding situations are given: the reduction coefficient K of the highway section traffic capacity in the three situations of the accident occupying one lane, the accident occupying two lanes, and the accident occupying three lanes, as shown in Table 1 below.

[0083] Table 1

[0084] When an accident occurs on a certain section of a highway, the actual traffic capacity C of the accident section can be calculated using the following formula: C=K×Q; K is the reduction factor, which can be directly selected from the corresponding value in Table 1; Q is the design capacity of the accident section on the highway, which can be directly determined according to the specific section, or calculated by converting the maximum hourly cross-sectional traffic volume of the ETC gantry on the section under normal circumstances into a standard vehicle. For details, please refer to the provisions on the maximum service traffic volume of highways in Appendix A of the "Technical Standards for Highway Engineering".

[0085] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A dynamic expansion control method for highway accident congestion based on ETC gantry, characterized in that: It includes the following steps: S1. Obtain accident information, including the accident occurrence time, accident location, lanes occupied by the accident, and accident vehicles; S2. Calculate the queue length at the accident scene; S3. Predict the congestion duration T, where the congestion duration consists of the rescue time T1, the breakdown clearance time T2, and the congestion dissipation time T3; S4. Conduct capacity expansion control in different regions. Divide regions according to the congestion duration. Starting from the accident location, successively divide the areas behind in the forward direction of the road into a control area and a buffer area. Judge the actual traffic capacity C of the accident section and conduct capacity expansion control: If C≠0 and the cross-sectional traffic volume Q1 of the upstream section < C, then enable dynamic speed limit for the control area, and at the same time take no measures for the buffer area; If C≠0 and the cross-sectional traffic volume Q1 of the upstream section ≥ C, then enable the emergency lane for the control area; at the same time, give a prompt to the vehicles in the buffer area to indicate that there is an accident section ahead; If C = 0, then enable the oncoming lane for the control area, and at the same time restrict the vehicles in the buffer area from entering the control area.

2. The method for dynamic capacity expansion control of highway accident congestion based on ETC gantry according to claim 1 is characterized in that: The length L of the control area c for: ； Among them, L is the queue length at the accident scene, Q2 is the cross-sectional traffic volume of the accident section, K2 is the traffic flow density of the accident section, Q1 is the cross-sectional traffic volume of the upstream section, and K1 is the traffic flow density of the upstream section.

3. The method for dynamic capacity expansion control of highway accident congestion based on ETC gantry according to claim 1 or 2, characterized in that: The length L of the buffer area b for: ； in, is the average vehicle speed on the upstream section, T is the congestion duration, T=T1+T2+T3.

4. The method for dynamic capacity expansion control of highway accident congestion based on ETC gantry according to claim 1 is characterized in that: In step S4, according to the number of lanes occupied by the accident and the traffic flow density K2 of the accident section, enable dynamic speed limit for the control area, specifically as follows: If the accident does not occupy any lanes, then judge the magnitude of the traffic flow density K2 of the accident section: if K2 < A1, then limit the maximum driving speed of the control area to VA1; if A1 ≤ K2 < A2, then limit the maximum driving speed of the control area to VA2; if A2 ≤ K2, then limit the maximum driving speed of the control area to VA3; Among them, A1 and A2 are set thresholds, VA3, VA2, and VA1 are set driving speeds, A1 < A2, and VA3 < VA2 < VA1; If the accident occupies 1 lane, then judge the magnitude of the traffic flow density K2 of the accident section: if K2 < B1, then limit the maximum driving speed of the control area to VB1; if B1 ≤ K2 < B2, then limit the maximum driving speed of the control area to VB2; if B2 ≤ K2, then limit the maximum driving speed of the control area to VB3; Among them, B1 and B2 are set thresholds, VB3, VB2, and VB1 are set driving speeds, B1 < B2, and VB3 < VB2 < VB1; If the accident occupies 2 or more lanes, then judge the magnitude of the traffic flow density K2 of the accident section: if K2 < C1, then limit the maximum driving speed of the control area to VC1; if C1 ≤ K2 < C2, then limit the maximum driving speed of the control area to VC2; if C2 ≤ K2, then limit the maximum driving speed of the control area to VC3; Among them, C1 and C2 are set thresholds, VC3, VC2, and VC1 are set driving speeds, C1 < C2, and VC3 < VC2 < VC1; Among them, C1 < C2 ≤ B1 < B2 ≤ A1 < A2, VC3 < VB3 < VA3, VC2 < VB2 < VA2, and VC1 < VB1 < VA1.

5. The method for dynamic capacity expansion control of highway accident congestion based on ETC gantry according to claim 1 is characterized in that: In step S2, based on the video surveillance of the ETC gantry on the highway, the queue length L at the accident scene is calculated as follows: Collect the video image of the ETC gantry where the accident occurred, that is, the first ETC gantry, perform target recognition on the image, and obtain the queue length L1 within the monitoring range of the first ECT gantry; Collect video images of each ETC gantries behind the accident site and obtain the queue length L within the monitoring range of the jth ECT gantry j ; j = 2, 3, ...; The maximum value of the ETC gantry monitoring range is L limit , if L1 <L limit , then the queue length at the accident site is L=L1; if L1=L limit , then search the ETC gantry in the rear until L is found. j <L limit , and L j-1 =L limit , then the queue length at the accident site is L=d 1，j +L j ; where d 1，j is the distance between the 1st ETC gantry and the jth ETC gantry.

6. The method for dynamic capacity expansion control of highway accident congestion based on ETC gantry according to claim 1 is characterized in that: In step S3, the rescue time T1 is the time required for the rescue vehicle to arrive at the accident site. The rescue time T1 is calculated as follows: Obtain the location information of the accident site; According to the GPS location information of all rescue vehicles, match the rescue vehicle closest to the accident site; According to the location information of the accident site and the location information of the rescue vehicle, a path planning algorithm is used to plan the shortest path for the rescue vehicle to reach the accident site; Based on the real-time traffic flow information of the accident section, the travel time of the rescue vehicle from the nearest toll station entrance to the accident site is predicted; The rescue time T1 is obtained by adding the travel time of the rescue vehicle from the nearest toll station entrance to the accident site to the normal time for the rescue vehicle to arrive at the nearest toll station entrance.

7. The method for dynamic capacity expansion control of highway accident congestion based on ETC gantry according to claim 1 is characterized in that: In step S3, the obstacle clearance time T2 is the time required to clear the accident obstacle on the road, and the obstacle clearance time T2 is calculated as follows: Collect historical clearance times for various accident types and construct datasets for different accident types; For the accident whose clearance time T2 is to be calculated, determine the accident type, select the corresponding data set according to the accident type, and select the median of the historical clearance time in the data set as the clearance time T2.

8. The method for dynamic capacity expansion control of highway accident congestion based on ETC gantry according to claim 1 is characterized in that: In step S3, the congestion dissipation time T3 is calculated based on the cross-sectional traffic volume Q2 and the traffic density K2 of the accident section, the cross-sectional traffic volume Q1 and the traffic density K1 of the upstream section, and the cross-sectional traffic volume Q3 and the traffic density K3 of the downstream section: ； Among them, the upstream section refers to the section behind the accident section along the direction of the road; the downstream section refers to the section in front of the accident section along the direction of the road; L is the queue length at the accident scene.

9. The method for dynamic capacity expansion control of highway accident congestion based on ETC gantry according to claim 1, 2, 4 or 8, characterized in that: By retrieving the ETC gantries corresponding to the accident section, upstream section and downstream section, the cross-sectional traffic volume of each section is obtained based on the cross-sectional traffic volume within the monitoring range of each ETC gantry; among which, the cross-sectional traffic volume within the monitoring range of the i-th ETC gantry is: ； Among them, Q id is the cross-section traffic volume within the monitoring range of the i-th ETC gantry, in pcu / h. The cross-section traffic volume refers to the number of vehicles passing through the road section within 1 hour, which is converted into standard vehicles for counting; k n is the conversion factor of the nth model, Q ind is the cross-sectional traffic volume of the nth vehicle type within the monitoring range of the i-th ETC gantry; By retrieving the ETC gantries corresponding to the accident section, upstream section and downstream section, the traffic density of each section is obtained based on the traffic density within the monitoring range of each ETC gantries; among which, the traffic density within the monitoring range of the i-th ETC gantry is: K id =H / h sid ; Among them, K id is the traffic density within the monitoring range of the ith ETC gantry. The traffic density refers to the number of vehicles within the monitoring range of the ETC gantry. sid is the headway distance within the monitoring range of the i-th ETC gantry; H is the road length within the monitoring range of the ETC gantry.

10. The method for dynamic capacity expansion control of highway accident congestion based on ETC gantry according to claim 1 is characterized in that: In step S4, the actual traffic capacity C of the accident section is calculated as follows: C=K×Q; wherein Q is the design traffic capacity of the accident section on the highway; and K is the reduction factor.

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