Road speed limit value optimization method
By conducting actual vehicle testing and GPS data collection on the speed limit section, dividing unit sections and determining the characteristic speed value, the problem of difficulty in optimizing speed limit value in the existing technology is solved, and fast and accurate speed limit value optimization is achieved, which improves traffic efficiency and traffic safety.
Patent Information
- Application Number
- CN202510136388.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-07
- Publication Date
- 2025-05-16
AI Technical Summary
The prior art is difficult to accurately optimize the road speed limit value without removing the speed limit signs and speed measurement equipment, resulting in a low speed limit value and affecting the traffic efficiency.
By conducting actual vehicle tests on the speed limit section, using the GPS positioner to collect test data, divide the speed limit section into several unit sections, and determine the characterization speed value of each unit section based on the test data, and finally determine the road speed limit value.
It has achieved rapid and accurate optimization of road speed limit values without conducting large-scale vehicle speed surveys and considering the impact of speed limit facilities, improving traffic efficiency and ensuring traffic safety.
Smart Images
Figure CN120014860A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of road traffic speed management, and in particular, relates to a method for optimizing road speed limit values. Background Art
[0002] As an important part of road traffic management, road speed limit management not only affects traffic safety, but also affects traffic efficiency. On the one hand, speeding will increase the risk of traffic accidents, so it is necessary to ensure traffic safety through speed limits; on the other hand, some road sections with good conditions will affect traffic efficiency due to too low speed limits, resulting in waste of road resources. Therefore, once it is found that the road speed limit value no longer meets the actual needs, it should be optimized in time. The current common practice is to use the 85th percentile speed as the speed limit value, but when speed limit facilities such as speed limit signs and speed measuring equipment have been set up on the road, the driver's speed choice is affected by them and cannot objectively reflect the road traffic conditions. The 85th percentile speed obtained on this basis is generally low and cannot be directly used as the road speed limit value. Therefore, how to accurately optimize the road speed limit value without having to remove speed limit facilities such as speed limit signs and speed measuring equipment 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 optimizing road speed limits. Starting from the actual work needs of the traffic management department, without the need to conduct large-scale vehicle speed surveys and without considering the impact of existing speed limit facilities on drivers, the road speed limit is determined by conducting actual vehicle tests on speed limit sections and dividing the speed limit sections into several unit sections for analysis. This method has the advantages of easy operation, low cost and high reliability.
[0004] The present application provides a method for optimizing a road speed limit value, comprising:
[0005] The driver selects the driving speed according to the road conditions, the following effect and the traffic environment to conduct a real vehicle test on the speed-limited road section, and uses a GPS locator to collect test data; wherein the test data includes: positioning time, position coordinates and instantaneous speed;
[0006] Match each test data to each unit section in the speed limit section;
[0007] For each unit road section, based on the test data matched to the unit road section, a representative speed value of the unit road section is obtained;
[0008] Based on the characteristic speed value of each unit road section, the road speed limit value of the speed-limited road section is determined.
[0009] Furthermore, the speed-limited road section is pre-divided into a plurality of unit sections by the following method:
[0010] Obtaining the design speed value of the speed-limited road section, and calculating the unit road section length based on the driver's reaction time;
[0011] The speed-limited road section is divided according to the length of the unit road section to obtain a plurality of unit road sections.
[0012] Furthermore, matching each test data to each unit section in the speed limit section includes:
[0013] Get the location coordinates of the starting point and end point of each unit section;
[0014] For each test data, determine whether the position coordinates of the test data and the position coordinates of the starting and ending points of each unit road section can form an acute triangle, and match the test data to the unit road section corresponding to the position coordinates of the starting and ending points that can form an acute triangle.
[0015] Furthermore, the following method is used to determine whether the position coordinates of the test data and the position coordinates of the starting point and the end point of each unit section can form an acute triangle:
[0016] For each unit road section, the position coordinates of the test data and the position coordinates of the starting point and the end point of the unit road section are used as the vertices of the triangle, and the straight-line distance between any two vertices is used as the side of the triangle, thereby forming the vertex angles corresponding to the three vertices respectively;
[0017] Use the law of cosines to calculate the cosines of the three vertex angles;
[0018] When the cosine values of the three vertex angles are all greater than 0, it is determined that the position coordinates of the test data and the position coordinates of the starting point and the end point of the unit section form an acute triangle;
[0019] When the cosine value of any vertex angle is not greater than 0, it is determined that the position coordinates of the test data and the position coordinates of the starting point and the end point of the unit section do not form an acute triangle.
[0020] Furthermore, obtaining the representative speed value of the unit road section based on the test data matched to the unit road section includes:
[0021] Extract the instantaneous speed of the test data matching the unit road section, and sort the instantaneous speeds in ascending order;
[0022] Calculate the 85% quantile based on the number of test data matched to the unit road segment;
[0023] When the 85% quantile is an integer, the instantaneous speed at the position corresponding to the 85% quantile is used as the representative speed value of the unit road section according to the above sorting;
[0024] When the 85% quantile is not an integer value, then according to the above sorting, the average of two speed values at adjacent positions of the 85% quantile is used as the representative speed value of the unit road section.
[0025] Furthermore, the determining of the road speed limit value of the speed limit section based on the characteristic speed value of each unit road section includes:
[0026] Sort the speed values of each unit section from small to large;
[0027] The 15% quantile was calculated based on the number of each unit road segment;
[0028] When the 15% quantile is an integer, the speed value corresponding to the 15% quantile is used as the theoretical speed limit value according to the above sorting;
[0029] When the 15% quantile is not an integer value, the average of the two speed values at adjacent positions of the 15% quantile is used as the theoretical speed limit value according to the above sorting;
[0030] The speed value with the smallest difference from the theoretical speed value is taken as the final road speed limit value.
[0031] The road speed limit optimization method provided in this application is based on the actual work needs of the traffic management department. Without the need to conduct large-scale vehicle speed surveys and without considering the impact of existing speed limit facilities on drivers, the road speed limit is determined by conducting real vehicle tests on speed limit sections and dividing the speed limit sections into several unit sections for analysis. This method has the advantages of easy operation, low cost and high reliability. Based on this method, the traffic management department can achieve timely, rapid and large-scale optimization of road speed limits, thereby maximizing traffic efficiency while ensuring traffic safety. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Figure 1 A flow chart of a method for optimizing road speed limits provided in an embodiment of the present application is shown. DETAILED DESCRIPTION
[0033] 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.
[0034] Please refer to Figure 1 Flow chart of the road speed limit optimization method shown in FIG. Figure 1 As shown, the method includes:
[0035] S101. The driver selects the driving speed according to the road conditions, the car-following effect and the traffic environment to conduct a real vehicle test on the speed-limited road section, and collects the test data using a GPS locator.
[0036] The test data includes: positioning time, position coordinates and instantaneous speed.
[0037] In this step, a real vehicle test is performed using a floating vehicle, test data of the speed limit section is collected at 1 second intervals, and the test data is imported into the PC for storage.
[0038] Here, in order to avoid the randomness of the actual vehicle test results, the actual vehicle test should be conducted no less than 5 times, and then the average value of the 5 actual vehicle tests should be used as the test data. At the same time, in order to reduce the impact of vehicle starting and stopping at both ends of the speed limit section on the actual vehicle test results, the range of each actual vehicle test should exceed the speed limit section range, and the excess range should be no less than 100 meters.
[0039] In addition, in order to ensure the safety and universality of actual vehicle testing, it is also stipulated that the driver's driving experience should be no less than 3 years. At the same time, it is ensured that the actual vehicle testing process is not affected by speed limit facilities such as speed limit signs and speed measuring equipment, so that the driver can choose the driving speed only based on road conditions, following effects and traffic environment.
[0040] S102: Match each test data to each unit section in the speed limit section.
[0041] In specific implementation, the speed-limited road section is pre-divided into a plurality of unit sections by the following method:
[0042] Step 201: Obtain the design speed value of the speed-limited road section, and calculate the unit road section length based on the driver's reaction time.
[0043] In this step, the calculation formula for the unit section length is as follows:
[0044] l=V l ·t l ; (1)
[0045] Where l is the length of the unit section, in meters, V l is the design speed value of the speed limit section, in m / s, t l is the driver's reaction time, usually 2.5s.
[0046] As an example, when the design speed value of the speed limit section is 60km / h, the length of the unit section can be calculated to be 42m.
[0047] Step 202: Divide the speed-limited road section according to the length of the unit road section to obtain a plurality of unit road sections.
[0048] In this step, since the length of the speed limit section is not necessarily an integer multiple of the unit section length, the length of the last unit section may be less than l. If the length of the last unit section is greater than l / 2, it is treated as an independent unit section, otherwise it is merged with the adjacent unit section.
[0049] In specific implementation, each test data is matched to each unit section in the speed limit section by the following method:
[0050] Step 1021: Obtain the location coordinates of the starting point and the end point of each unit road section.
[0051] In this step, in order to reduce the on-site workload of determining the road speed limit and reduce the safety risks of on-site surveyors, the longitude and latitude coordinates of the starting and ending points of each unit section can be directly collected using map processing software, and the data can be stored on the PC to provide a data basis for the subsequent matching of test data and unit sections. However, for newly built roads, the map processing software may not be able to provide the latest road information. In this case, a high-precision GPS locator can be used to directly obtain the longitude and latitude coordinates of the starting and ending points of the unit section by marking points on site.
[0052] Step 1022: for each test data, determine whether the position coordinates of the test data and the position coordinates of the starting point and the end point of each unit road section can form an acute triangle, and match the test data to the unit road section corresponding to the position coordinates of the starting point and the end point that can form an acute triangle.
[0053] In this step, the unit road section corresponding to the test data is determined by matching the test data with each unit road section one by one.
[0054] In specific implementation, the following method is used to determine whether the position coordinates of the test data and the position coordinates of the starting point and the end point of each unit section can form an acute triangle:
[0055] Step 301: For each unit road section, the position coordinates of the test data and the position coordinates of the starting point and the end point of the unit road section are used as the vertices of the triangle, and the straight-line distance between any two vertices is used as the side of the triangle, thereby forming the vertex angles corresponding to the three vertices.
[0056] As an example, the position coordinates of the test data and the position coordinates of the starting point and the end point of the unit section are respectively used as the vertices A(x1,y1), B(x2,y2), and C(x3,y3) of the triangle, and the lengths of its three sides AB, BC, and AC are respectively:
[0057]
[0058] Step 302: Calculate the cosine values of the three vertex angles using the cosine theorem.
[0059] As an example, taking the vertex angle B as an example, the cosine value is calculated according to the following formula:
[0060]
[0061] Step 303: When the cosine values of the three vertex angles are all greater than 0, it is determined that the position coordinates of the test data and the position coordinates of the starting point and the end point of the unit section form an acute triangle.
[0062] Step 304: When the cosine value of any vertex angle is not greater than 0, it is determined that the position coordinates of the test data and the position coordinates of the starting point and the end point of the unit section do not form an acute triangle.
[0063] In this step, if cosB>0, B is an acute angle. At the same time, if cosA>0 and cosC>0, the triangle is an acute triangle.
[0064] S103 . For each unit road section, based on the test data matched to the unit road section, obtain a representative speed value of the unit road section.
[0065] In specific implementation, the representative speed value of the unit section is obtained by the following method:
[0066] Step 1031: extract the instantaneous speeds of the test data matched to the unit road section, and sort the instantaneous speeds in ascending order.
[0067] Step 1032: Calculate the 85% quantile based on the number of test data matched to the unit road segment.
[0068] When the 85% quantile is an integer, step 1033 is executed to use the instantaneous speed at the position corresponding to the 85% quantile as the representative speed value of the unit road section according to the sorting.
[0069] When the 85% quantile is not an integer value, step 1034 is executed to use the average of two speed values at adjacent positions of the 85% quantile as the representative speed value of the unit road section according to the sorting.
[0070] In this step, the 85% quantile is calculated by the following formula (3). If p is an integer, the pth instantaneous speed value is used as the representative speed value according to the order of the instantaneous speeds. Otherwise, the average of the two instantaneous speed values adjacent to the p position is used as the representative speed value.
[0071] p=0.85n; (3)
[0072] Where n is the number of test data matched to the unit road segment.
[0073] As an example, suppose a unit road section successfully matches 5 test data, and the instantaneous speeds are arranged from small to large as 10km / h, 20km / h, 30km / h, 40km / h and 50km / h, then p=4.25. Since p is not an integer, the average of the 4th and 5th instantaneous speed values 45km / h is taken as the representative speed value of the unit road section.
[0074] S104: Determine the road speed limit value of the speed-limited road section based on the characteristic speed value of each unit road section.
[0075] In specific implementation, the road speed limit value of the speed limit section is determined by the following method:
[0076] Step 1041: sort the speed values of each unit road section from small to large.
[0077] Step 1042: Calculate the 15% quantile based on the number of each unit road segment.
[0078] When the 15% quantile is an integer, step 1043 is executed to use the speed value corresponding to the 15% quantile as the theoretical speed limit value according to the sorting.
[0079] When the 15% quantile is not an integer value, step 1044 is executed to use the average of two speed-characterizing values at adjacent positions of the 15% quantile as the theoretical speed limit value according to the sorting.
[0080] Step 1045: The speed value with the smallest difference from the theoretical speed value is taken as the final road speed limit value.
[0081] In this step, the 15% quantile is calculated by the following formula (4). If q is an integer, the qth representative speed value is taken as the theoretical speed limit value. Otherwise, the average of the two representative speed values adjacent to the qth position is taken as the theoretical speed limit value.
[0082] q=0.15m; (4)
[0083] Where m is the number of each unit section.
[0084] Then, the speed value with the smallest difference from the theoretical speed limit is taken as the final road speed limit.
[0085] As an example, assuming that a speed limit in Luton contains 200 unit sections, then q=30. Since q is an integer, the 30th speed value is taken as the theoretical speed limit. At the same time, assuming that the theoretical speed limit is 64km / h, the final road speed limit is 60km / h. Assuming that the theoretical speed limit is 66km / h, the final road speed limit is 70km / h.
[0086] 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 method for optimizing road speed limit, characterized in that: The method comprises: The driver selects the driving speed according to the road conditions, the following effect and the traffic environment to conduct a real vehicle test on the speed-limited road section, and uses a GPS locator to collect test data; wherein the test data includes: positioning time, position coordinates and instantaneous speed; Match each test data to each unit section in the speed limit section; For each unit road section, based on the test data matched to the unit road section, a representative speed value of the unit road section is obtained; Based on the characteristic speed value of each unit road section, the road speed limit value of the speed-limited road section is determined.
2. The method according to claim 1, characterized in that The speed limit section is pre-divided into a plurality of unit sections by the following method: Obtaining the design speed value of the speed-limited road section, and calculating the unit road section length based on the driver's reaction time; The speed-limited road section is divided according to the length of the unit road section to obtain a plurality of unit road sections.
3. The method according to claim 1, characterized in that The step of matching each test data to each unit road section in the speed limit road section includes: Get the location coordinates of the starting point and end point of each unit section; For each test data, determine whether the position coordinates of the test data and the position coordinates of the starting and ending points of each unit road section can form an acute triangle, and match the test data to the unit road section corresponding to the position coordinates of the starting and ending points that can form an acute triangle.
4. The method according to claim 3, characterized in that The following method is used to determine whether the position coordinates of the test data and the position coordinates of the starting point and the end point of each unit section can form an acute triangle: For each unit section, the position coordinates of the test data and the position coordinates of the starting point and the end point of the unit section are used as the vertices of the triangle, and the straight-line distance between any two vertices is used as the side of the triangle, thereby forming the vertex angles corresponding to the three vertices respectively; Use the law of cosines to calculate the cosines of the three vertex angles; When the cosine values of the three vertex angles are all greater than 0, it is determined that the position coordinates of the test data and the position coordinates of the starting point and the end point of the unit section form an acute triangle; When the cosine value of any vertex angle is not greater than 0, it is determined that the position coordinates of the test data and the position coordinates of the starting point and the end point of the unit section do not form an acute triangle.
5. The method according to claim 1, characterized in that The obtaining the representative speed value of the unit road section based on the test data matched to the unit road section includes: Extract the instantaneous speed of the test data matching the unit road section, and sort the instantaneous speeds in ascending order; Calculate the 85% quantile based on the number of test data matched to the unit road segment; When the 85% quantile is an integer, the instantaneous speed at the position corresponding to the 85% quantile is used as the representative speed value of the unit road section according to the above sorting; When the 85% quantile is not an integer value, then according to the above sorting, the average of two speed values at adjacent positions of the 85% quantile is used as the representative speed value of the unit road section.
6. The method according to claim 1, characterized in that The determining of the road speed limit value of the speed-limited road section based on the characteristic speed value of each unit road section includes: Sort the speed values of each unit section from small to large; The 15% quantile was calculated based on the number of each unit road segment; When the 15% quantile is an integer, the speed value corresponding to the 15% quantile is used as the theoretical speed limit value according to the above sorting; When the 15% quantile is not an integer value, the average of the two speed values at adjacent positions of the 15% quantile is used as the theoretical speed limit value according to the above sorting; The speed value with the smallest difference from the theoretical speed value is taken as the final road speed limit value.