Pedestrian crossing traffic accident risk assessment method

Abstract

The invention provides a pedestrian crossing traffic accident risk assessment method. The method comprises the steps of obtaining a target position of a pedestrian crossing and coordinates of a target position of an upstream road section of the pedestrian crossing; acquiring test data of the real vehicle test process of the upstream road section of the pedestrian crosswalk; wherein the test data comprises positioning time, position coordinates and instantaneous speed; based on the target position of the pedestrian crossing and the coordinate of the target position of the upstream road section of the pedestrian crossing, screening target test data in the traffic safety influence range from the test data; and calculating a traffic accident risk index of the pedestrian crossing based on the target test data so as to evaluate a traffic accident risk level of the pedestrian crossing. The method is easy to operate, low in cost and high in reliability, and the traffic accident risk level of the pedestrian crosswalk of the road section can be evaluated only by collecting test data within the traffic safety influence range of the upstream road section of the pedestrian crosswalk of the road section.

Description

Technical Field

[0001] The present application belongs to the technical field of road traffic accident risk assessment, and in particular, relates to a method for assessing the risk of traffic accidents at pedestrian crossings. Background Art

[0002] In terms of road types, the proportion of traffic accidents on urban roads has shown an increasing trend in recent years, among which more traffic accidents occur at crosswalks. The causes of frequent traffic accidents at crosswalks include long crossing distances, poor sight distance conditions, lack of traffic facilities, improper speed management, etc. Therefore, under the current conditions where traffic management departments lack manpower, financial resources, and energy, how to quickly, accurately, and at low cost evaluate the risk of traffic accidents at crosswalks has become a technical problem that needs to be solved urgently. Summary of the invention

[0003] In view of this, the purpose of this application is to provide a method for assessing the risk of traffic accidents at pedestrian crossings. The method is easy to operate, low-cost and highly reliable, and can assess the traffic accident risk level of a section of pedestrian crossings simply by collecting test data within the traffic safety influence range of the upstream section of the section of pedestrian crossings.

[0004] This application provides a method for assessing the risk of pedestrian crossing traffic accidents, including:

[0005] Obtain the coordinates of the target location of the crosswalk and the target location of the upstream section of the crosswalk;

[0006] Collecting test data of the actual vehicle test process on the upstream section of the pedestrian crossing; wherein the test data includes: positioning time, position coordinates and instantaneous speed;

[0007] Based on the coordinates of the target position of the crosswalk and the target position of the upstream section of the crosswalk, the target test data within the traffic safety impact range are screened out from the test data;

[0008] Based on the target test data, a traffic accident risk index of the crosswalk is calculated to evaluate the traffic accident risk level of the crosswalk.

[0009] Furthermore, before obtaining the coordinates of the target position of the crosswalk and the target position of the upstream section of the crosswalk, the method further includes:

[0010] According to the up and down directions of the road section where the crosswalk is located, the intersection position of the horizontal axis and the vertical axis of the crosswalk is determined as the target position of the crosswalk;

[0011] Obtaining the design speed of the upstream section of the crosswalk to determine the stopping sight distance of the crosswalk;

[0012] Based on the target position of the crosswalk and the stopping sight distance, determine the target position of the upstream section of the crosswalk.

[0013] Further, the obtaining the design speed of the upstream section of the crosswalk to determine the stopping sight distance of the crosswalk includes:

[0014] Based on the design speed of the upstream section of the crosswalk, calculate the driver's discrimination distance, the driver's reaction distance, and the vehicle braking distance to obtain the stopping sight distance of the crosswalk;

[0015] Or,

[0016] Determine the stopping sight distance of the crosswalk according to the corresponding relationship between the design speed and the stopping sight distance.

[0017] Further, calculate the driver's discrimination distance, the driver's reaction distance, and the vehicle braking distance through the following methods:

[0018] Based on the design speed of the upstream section of the crosswalk and the driver's discrimination time, calculate the driver's discrimination distance;

[0019] Based on the design speed of the upstream section of the crosswalk and the driver's reaction time, calculate the driver's reaction distance;

[0020] Based on the design speed of the upstream section of the crosswalk, the road surface friction coefficient, and the road longitudinal gradient, calculate the vehicle braking distance.

[0021] Further, the screening out of the target test data within the traffic safety influence range from the test data based on the coordinates of the target position of the crosswalk and the target position of the upstream section of the crosswalk includes:

[0022] For each test data, extract the position coordinates of this test data;

[0023] Take the position coordinates of this test data, the coordinates of the target position of the crosswalk, and the coordinates of the target position of the upstream section of the crosswalk as the vertices of a triangle, and take the straight-line distance between any two vertices as the sides of the triangle, so as to form the apex angles corresponding to the three vertices;

[0024] Use the cosine theorem to calculate the cosine values of the three apex angles to determine whether this test data is within the traffic safety influence range;

[0025] Extract the test data that is determined to be within the traffic safety influence range to obtain the target test data.

[0026] Further, determine whether this test data is within the traffic safety influence range through the following methods:

[0027] Taking the vertex angle corresponding to the coordinates of the target position of the crosswalk and the coordinates of the target position of the upstream section of the crosswalk as a reference angle;

[0028] When the cosine values ​​of the two reference angles are both greater than 0, the test data is judged to be within the traffic safety impact range;

[0029] When the cosine value of any reference angle is not greater than 0, it is judged that the test data is not within the range of traffic safety impact.

[0030] Furthermore, the traffic accident risk index of the crosswalk is calculated by the following formula:

[0031]

[0032] Where S is the traffic accident risk index of the pedestrian crossing; is the average speed of the actual vehicle test process (km / h); V l The speed limit of the road upstream of the crosswalk (km / h); is the speed value of the ith test data of the jth actual vehicle test (km / h); n j is the number of test data of the jth actual vehicle test; m is the number of actual vehicle tests.

[0033] Furthermore, the traffic accident risk level of the crosswalk is evaluated by the following method:

[0034] comparing the traffic accident risk index of the crosswalk with a preset traffic accident risk threshold of the crosswalk;

[0035] When the traffic accident risk index of the crosswalk is less than or equal to 0.2, it is judged that the traffic accident risk of the crosswalk is low;

[0036] When the traffic accident risk index of the crosswalk is in the interval of (0.2, 0.4], it is judged that the traffic accident risk of the crosswalk is low;

[0037] When the traffic accident risk index of the crosswalk is in the interval of (0.4, 0.6], it is judged that the traffic accident risk of the crosswalk is high;

[0038] When the traffic accident risk index of the crosswalk is in the range of (0.6, 0.8], it is judged that the traffic accident risk of the crosswalk is high;

[0039] When the traffic accident risk index of the crosswalk is greater than 0.8, it is determined that the traffic accident risk of the crosswalk is extremely high.

[0040] The pedestrian crossing traffic accident risk assessment method provided by this application focuses on the difficulties and pain points of the work of traffic police. In the face of the complex causes of traffic accidents at pedestrian crossings and the reality of the large number of pedestrian crossings on road sections in my country, it can evaluate the traffic accident risk level of road section pedestrian crossings by only collecting test data within the traffic safety impact range of the upstream road section of the road section pedestrian crossing. The method is easy to operate, low in cost and highly reliable, and at the same time helps traffic management departments to carry out more in-depth traffic safety hazard inspections for road section pedestrian crossings with higher risks, and then improve the traffic safety level of road section pedestrian crossings through comprehensive rectification measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A flow chart of a pedestrian crossing traffic accident risk assessment method provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the technical solution more clear, the technical solution is further described in detail below in conjunction with specific implementation methods. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the technical solution.

[0043] See also Figure 1 The flowchart of the pedestrian crossing traffic accident risk assessment method provided by the embodiment of the present application is shown. Figure 1 As shown, the method includes:

[0044] S101. Obtain the coordinates of a target position of a crosswalk and a target position of an upstream section of the crosswalk.

[0045] In this step, the Beidou or GPS locator carried by the probe vehicle is used to collect the coordinates of the target position of the crosswalk on the road section and the target position of the section upstream of the crosswalk, and the data is stored in the on-board information storage device, thereby providing a data basis for the risk assessment of traffic accidents at crosswalks.

[0046] In addition, before obtaining the coordinates of the target position of the crosswalk and the target position of the upstream section of the crosswalk, the method further includes:

[0047] Step 201: Determine the intersection of the horizontal axis and the vertical axis of the crosswalk as the target position of the crosswalk according to the up and down directions of the road section where the crosswalk is located.

[0048] Step 202: Obtain the design speed of the upstream section of the crosswalk to determine the stopping sight distance of the crosswalk.

[0049] In specific implementation, the stopping sight distance of the pedestrian crossing is determined by the following method:

[0050] Based on the design speed of the upstream section of the crosswalk, the driver's identification distance, the driver's reaction distance and the vehicle's braking distance are calculated to obtain the stopping sight distance of the crosswalk.

[0051] The driver identification distance, driver reaction distance and vehicle braking distance are calculated in the following manner:

[0052] Step 301: Calculate the driver identification distance based on the design speed of the upstream section of the crosswalk and the driver identification time.

[0053] Step 302: Calculate the driver's reaction distance based on the design speed of the upstream section of the crosswalk and the driver's reaction time.

[0054] Step 303: Calculate the vehicle braking distance based on the design speed, road friction coefficient and road longitudinal slope of the upstream section of the crosswalk.

[0055] As an example, first, the driver identification distance, driver reaction distance and vehicle braking distance are calculated by the following formula (1):

[0056]

[0057] In the formula, l 1 Distance for driver identification (m); t 1 is the driver identification time (s), generally 1.5s; v d The design speed of the upstream section of the crosswalk (km / h); l 2 is the driver's reaction distance (m); t 2 is the driver's reaction time (s), generally 0.4s; l 3 is the vehicle braking distance (m); is the road friction coefficient, i is the longitudinal slope of the road (%), uphill is positive and downhill is negative.

[0058] Then, the stopping sight distance of the pedestrian crossing is obtained by the following formula (2):

[0059] I s =I 1 +I 2 +I 3 +I 4 ; (2)

[0060] In the formula, l s is the stopping sight distance (m); l 4 For the safety distance (m), 10m can be used.

[0061] In specific implementation, the stopping sight distance of the pedestrian crossing is also determined by the following method:

[0062] The stopping sight distance of the pedestrian crossing is determined according to the corresponding relationship between the design speed and the stopping sight distance.

[0063] Here, since the process of calculating the stopping sight distance based on the above steps 301-303 is relatively complicated, the stopping sight distance of the crosswalk may also be determined according to the corresponding relationship between the design speed and the stopping sight distance.

[0064] As an example, the "Highway Route Design Specifications" (JTG D20-2017) stipulates that the design speed and stopping sight distance should satisfy the corresponding relationship shown in Table 1 to ensure driving safety.

[0065] Table 1. Stopping sight distance values ​​specified in the Highway Route Design Specifications (JTG D20-2017)

[0066]

[0067] Step 203: Determine the target position of the upstream section of the crosswalk based on the target position of the crosswalk and the stopping sight distance.

[0068] Based on the above steps 201-203, the target position of the crosswalk and the target position of the upstream section of the crosswalk are determined. Specifically: first, the intersection of the horizontal axis and the vertical axis of the crosswalk is selected as the target position of the crosswalk. Here, it should be noted that the up and down directions of the section where the crosswalk is located are distinguished, so as to determine the target positions of the crosswalk respectively; then, the target position of the upstream section of the crosswalk is determined with the target position of the crosswalk as the starting point and the parking sight distance as the distance.

[0069] S102: Collect test data of a real vehicle test process on the upstream section of the pedestrian crossing.

[0070] Wherein, the test data includes: positioning time, position coordinates and instantaneous speed;

[0071] In this step, the Beidou or GPS locator carried by the probe vehicle is used to collect test data from the actual vehicle test process on the upstream section of the crosswalk at a sampling interval of 1 second, and the data is stored in the on-board information storage device, thereby providing a data basis for the traffic accident risk assessment of the crosswalk.

[0072] Here, in order to reduce the impact of random factors on the actual vehicle test results of the probe car, the actual vehicle test should be no less than 9 times. At the same time, the scope of each actual vehicle test should exceed the traffic safety impact range of the crosswalk of the road section, and the excess range should be no less than 100 meters.

[0073] S103: based on the coordinates of the target position of the crosswalk and the target position of the upstream section of the crosswalk, select target test data within the traffic safety impact range from the test data.

[0074] In this step, since the scope of the actual vehicle test of the probe car exceeds the traffic safety impact range of the crosswalk, the test data includes both data within the traffic safety impact range and data outside the traffic safety impact range; however, assessing the traffic accident risk of the crosswalk requires the use of test data within the traffic safety impact range, so for each test data, it is necessary to determine whether it is within the traffic safety impact range.

[0075] In specific implementation, target test data within the traffic safety impact range is screened out from the test data in the following manner:

[0076] Step 1031: For each test data, extract the position coordinates of the test data.

[0077] Step 1032: Use the position coordinates of the test data, the coordinates of the target position of the crosswalk, and the coordinates of the target position of the upstream section of the crosswalk as vertices of a triangle, and use the straight-line distance between any two vertices as the side of the triangle, thereby forming vertex angles corresponding to the three vertices.

[0078] Step 1033: Calculate the cosine values ​​of the three vertex angles using the cosine theorem to determine whether the test data is within the traffic safety impact range.

[0079] As an example, the above steps 1031-1033 can be mapped to solve a trigonometric function problem. Specifically: First, assume that the position coordinates of the test data are A(x 1 ,y 1 ), the coordinates of the target position of the crosswalk are B(x 2 ,y 2 ), the coordinates of the target position of the upstream section of the crosswalk are C(x 3 ,y 3 ); Secondly, based on the coordinates of the three vertices of triangle ABC, the following formula (3) is used to calculate the distance between any two points, namely the sides AB, BC and AC of triangle ABC:

[0080]

[0081] Finally, use the cosine theorem to calculate the cosine values ​​of the three vertex angles of triangle ABC, where the calculation formulas for vertex angle B and vertex angle C are as follows:

[0082]

[0083] In specific implementation, whether the test data is within the scope of traffic safety impact is determined by the following methods:

[0084] Step 401: Take the vertex angle corresponding to the coordinates of the target position of the crosswalk and the coordinates of the target position of the upstream section of the crosswalk as a reference angle.

[0085] When the cosine values ​​of the two reference angles are both greater than 0, step 402 is executed to determine whether the test data is within the traffic safety impact range.

[0086] When the cosine value of any reference angle is not greater than 0, step 403 is executed to determine that the test data is not within the traffic safety impact range.

[0087] As an example, the above steps 401-403 can be mapped to solving trigonometric function problems. Specifically: if the cosine values ​​of the vertex angle B and the vertex angle C are both greater than 0, it means that both are acute angles. At this time, it is considered that the position coordinates of the test data are within the traffic safety influence range of the crosswalk, that is, the test data is judged to be within the traffic safety influence range; otherwise, it is considered that the position coordinates of the test data are outside the traffic safety influence range of the crosswalk.

[0088] Step 1034: extract the test data judged to be within the traffic safety impact range to obtain target test data.

[0089] S104. Calculate a traffic accident risk index of the crosswalk based on the target test data to evaluate the traffic accident risk level of the crosswalk.

[0090] In specific implementation, the traffic accident risk index of the crosswalk is calculated by the following formula (5):

[0091]

[0092] Where S is the traffic accident risk index of the pedestrian crossing; is the average speed of the actual vehicle test process (km / h); V l The speed limit of the road upstream of the crosswalk (km / h); is the speed value of the ith test data of the jth actual vehicle test (km / h); n j is the number of test data of the jth actual vehicle test; m is the number of actual vehicle tests.

[0093] In specific implementation, the traffic accident risk level of the pedestrian crossing is evaluated by the following methods:

[0094] comparing the traffic accident risk index of the crosswalk with a preset traffic accident risk threshold of the crosswalk;

[0095] When the traffic accident risk index of the crosswalk is less than or equal to 0.2, it is judged that the traffic accident risk of the crosswalk is low;

[0096] When the traffic accident risk index of the crosswalk is in the interval of (0.2, 0.4], it is judged that the traffic accident risk of the crosswalk is low;

[0097] When the traffic accident risk index of the crosswalk is in the interval of (0.4, 0.6], it is judged that the traffic accident risk of the crosswalk is high;

[0098] When the traffic accident risk index of the crosswalk is in the range of (0.6, 0.8], it is judged that the traffic accident risk of the crosswalk is high;

[0099] When the traffic accident risk index of the crosswalk is greater than 0.8, it is determined that the traffic accident risk of the crosswalk is extremely high.

[0100] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, many changes can be made in the specific implementation methods and application scopes based on the ideas of the present technical content. As long as these changes do not deviate from the concept of the present invention, they all fall within the scope of protection of this patent.

Claims

1. A pedestrian crossing traffic accident risk assessment method, characterized in that: The method comprises: Obtain the coordinates of the target location of the crosswalk and the target location of the upstream section of the crosswalk; Collecting test data of the actual vehicle test process on the upstream section of the pedestrian crossing; wherein the test data includes: positioning time, position coordinates and instantaneous speed; Based on the coordinates of the target position of the crosswalk and the target position of the upstream section of the crosswalk, the target test data within the traffic safety impact range are screened out from the test data; Based on the target test data, a traffic accident risk index of the crosswalk is calculated to evaluate the traffic accident risk level of the crosswalk.

2. The method according to claim 1, characterized in that Before obtaining the coordinates of the target position of the crosswalk and the target position of the upstream section of the crosswalk, the method further includes: According to the up and down directions of the road section where the crosswalk is located, the intersection position of the horizontal axis and the vertical axis of the crosswalk is determined as the target position of the crosswalk; Obtaining the design speed of the upstream section of the crosswalk to determine the stopping sight distance of the crosswalk; Based on the target position of the crosswalk and the stopping sight distance, a target position of the upstream section of the crosswalk is determined.

3. The method according to claim 2, characterized in that The obtaining of the design speed of the upstream section of the crosswalk to determine the stopping sight distance of the crosswalk includes: Based on the design speed of the upstream section of the crosswalk, the driver identification distance, the driver reaction distance and the vehicle braking distance are calculated to obtain the stopping sight distance of the crosswalk; or, The stopping sight distance of the pedestrian crossing is determined according to the corresponding relationship between the design speed and the stopping sight distance.

4. The method according to claim 3, characterized in that The driver identification distance, driver reaction distance and vehicle braking distance are calculated by the following method: Calculating the driver identification distance based on the design speed of the upstream section of the crosswalk and the driver identification time; Calculating the driver's reaction distance based on the design speed of the upstream section of the crosswalk and the driver's reaction time; The vehicle braking distance is calculated based on the design speed of the upstream section of the crosswalk, the road surface friction coefficient and the longitudinal slope of the road.

5. The method according to claim 1, characterized in that The target test data within the traffic safety impact range is screened out from the test data based on the target position of the crosswalk and the coordinates of the target position of the upstream section of the crosswalk, including: For each test data, extract the position coordinates of the test data; The position coordinates of the test data, the coordinates of the target position of the crosswalk, and the coordinates of the target position of the upstream section of the crosswalk are used as vertices of a triangle, and the straight-line distance between any two vertices is used as a side of the triangle, thereby forming vertex angles corresponding to the three vertices respectively; Use the cosine theorem to calculate the cosine values ​​of the three vertex angles to determine whether the test data is within the traffic safety impact range; The test data judged to be within the scope of traffic safety impact are extracted to obtain the target test data.

6. The method according to claim 5, characterized in that Whether the test data is within the scope of traffic safety impact is determined by the following methods: Taking the vertex angle corresponding to the coordinates of the target position of the crosswalk and the coordinates of the target position of the upstream section of the crosswalk as a reference angle; When the cosine values ​​of the two reference angles are both greater than 0, the test data is judged to be within the traffic safety impact range; When the cosine value of any reference angle is not greater than 0, it is judged that the test data is not within the range of traffic safety impact.

7. The method according to claim 1, characterized in that The traffic accident risk index of the crosswalk is calculated by the following formula: Where S is the traffic accident risk index of the pedestrian crossing; is the average speed of the actual vehicle test process (km / h); V l The speed limit of the road upstream of the crosswalk (km / h); is the speed value of the ith test data of the jth actual vehicle test (km / h); n j is the number of test data of the jth actual vehicle test; m is the number of actual vehicle tests.

8. The method according to claim 1, characterized in that The traffic accident risk level of the pedestrian crossing is assessed by: comparing the traffic accident risk index of the crosswalk with a preset traffic accident risk threshold of the crosswalk; When the traffic accident risk index of the crosswalk is less than or equal to 0.2, it is judged that the traffic accident risk of the crosswalk is low; When the traffic accident risk index of the crosswalk is in the interval of (0.2, 0.4], it is judged that the traffic accident risk of the crosswalk is low; When the traffic accident risk index of the crosswalk is in the interval of (0.4, 0.6], it is judged that the traffic accident risk of the crosswalk is high; When the traffic accident risk index of the crosswalk is in the range of (0.6, 0.8], it is judged that the traffic accident risk of the crosswalk is high; When the traffic accident risk index of the crosswalk is greater than 0.8, it is determined that the traffic accident risk of the crosswalk is extremely high.

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