Urban road short path overflow problem diagnosis and measure recommendation method

Abstract

The technical scheme of the invention discloses an urban road short path overflow problem diagnosis and measure recommendation method. According to the method, short-path overflow alarm is carried out through short-distance release section screening, short-path overflow index calculation, short-path overflow judgment and the like on the basis of data such as an urban road network topological structure, release section flow and release section speed, and measures and suggestions of downstream dredging and upstream interception are given. According to the method, research on road sections with short intervals needs to be completed on the basis of frequent congestion and real-time congestion judgment, and conflicts with other digital traffic measures such as signal optimization and traffic channelization optimization do not exist. According to the invention, the fusion of the historical congestion characteristics and the real-time congestion characteristics of the short-distance release section is realized, and a downstream dredging or upstream interception measure for effectively relieving the short-path overflow phenomenon is provided for the real-time congestion overflow characteristics, and the measure can effectively avoid the upstream and downstream spreading of congestion overflow.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of urban road short path overflow problem diagnosis and measure recommendation method, belong to intelligent transportation technical field. BACKGROUND

[0002] With the development of social economy, the national motor vehicle population increases year by year, the existing road structure layout in the core area of large and medium-sized cities cannot be reconstructed on a large scale due to land restrictions, and part of the road network has entered the large and medium repair period, so the imbalance between demand and supply is increasing year by year, and the congestion index is increasing year by year. Different congestion phenomena correspond to different solutions, especially in the urban center, the distance between intersections is relatively short, and the probability of congestion overflow is larger, which needs effective management measures to alleviate the congestion phenomenon of urban roads. Therefore, for the short road congestion overflow problem, fine research and targeted traffic management measures need to be further studied.

[0003] The existing congestion research and judgment generally includes the following categories: first, more inclined to based on different data sources, using traffic speed indicators to complete traffic state discrimination, or integrating multi-source data, comprehensive multiple indicators to discriminate traffic state, this kind of method is mainly to research and judge the real-time congestion of urban roads, without fine analysis of the phenomenon or cause of congestion, and it is also impossible to propose targeted suggestions and measures. Second, based on historical traffic state to complete the discrimination of frequently occurring congestion, which can well reflect the normal characteristics of urban roads and help to propose measures to alleviate road congestion. Third, for frequently occurring congestion, signal optimization, traffic channelization optimization and other suggestions are proposed to alleviate urban road congestion, but traffic congestion has a certain randomness, and the historical frequent characteristics often cannot accurately express the real-time characteristics. The suggestions given by the historical characteristics cannot really alleviate the road congestion to some extent. SUMMARY

[0004] The purpose of the present application is to solve the structural characteristics of urban road network, traffic operation characteristics, and analyze the short path overflow problem of urban roads.

[0005] In order to achieve the above purpose, the technical scheme of the present application discloses a kind of urban road short path overflow problem diagnosis and measure recommendation method, which is characterized by comprising the following steps:

[0006] Step 1, screening to obtain frequently occurring congestion release section, and extracting lane flow, turning flow, release section speed and release section length corresponding to the release section, and then screening out short distance release section, wherein the release section length of short distance release section is less than short path distance threshold value;

[0007] Step 2, calculating lane short path index and release section short path index, wherein:

[0008] The lane short path index of the lane i j is denoted as lane_short_index ij Then, we have:

[0009] lane_short_index ij = lane_volume ij / lane_speed ij / issuesect_length i *10000

[0010] In the formula, lane_volume ij is the traffic volume of the lane i j, and lane_speed ij is the speed of the lane i j.

[0011] The issue section short path index of the issue section i is denoted as issuesect_short_index i Then, we have:

[0012]

[0013] In the formula, n i is the number of lanes of the issue section i.

[0014] Step 3, if the issue section short path index of the issue section i issuesect_short_index i continuously exceeds the short path overflow threshold for multiple periods, a path overflow alarm is given.

[0015] Step 4, downstream diversion suggestions and upstream interception suggestions are obtained, wherein:

[0016] The downstream diversion suggestions are obtained by the following steps:

[0017] Step 401, according to the road network topology relationship, the downstream traffic direction section numbers of the issue section are extracted.

[0018] Step 402, based on the history and real-time data table of the recurrent congestion issue section, according to the downstream direction section numbers of the issue section i, it is judged whether the downstream issue section with the downstream direction section as the terminal point is a recurrent congestion issue section or is in real-time congestion, and the downstream direction section number k uncongestion of the non-recurrent congestion and current non-congestion is recorded.

[0019] Step 403, based on the non-congestion downstream issue section number k uncongestion , according to the downstream direction section number, it is judged whether the issue section with the downstream section number of the issue section i as the terminal point is a short path, if it is a short path, the downstream direction section number k unshort of the non-congestion and non-short path is recorded, kunshort ∈k uncongestion ;

[0020] Step 404, based on non-congestion, non-short path downstream section number k unshort , based on the current release section i traffic, release section i steering traffic filter traffic larger steering, and record the corresponding downstream section number k bigvol , k bigvol ∈k unshort ;

[0021] Step 405, based on the length of the downstream release section, the number of lanes, and the average length of each vehicle to calculate the number of vehicles that can be accommodated in the release section:

[0022]

[0023] In the formula, is the maximum number of vehicles that can be accommodated in the release section corresponding to the downstream section k of the release section i, and aver_vehicle_length is the average length of each vehicle, is the number of lanes of the release section corresponding to the downstream section k of the release section i;

[0024] Based on the larger traffic steering corresponding to the downstream section number k bigvol , judge whether its traffic inflow downstream has pressure, when meet:

[0025]

[0026] Record the downstream section number k littlesink , k littlesink ∈k bigvol ;

[0027] If k littlesink is not empty, then the sections in the downstream set k littlesink can be dredged, that is, the problem suggestion issue_suggest i = ′ downstream dredging ′, the corresponding section number of the proposed measures issue_sect i = k, where k ∈ k littlesink ;

[0028] The following steps are used to obtain the upstream interception suggestion:

[0029] Step 4-1, according to the road network topological relationship, extract the upstream traffic section number of the release section

[0030] Step 4-2: Based on the upstream incoming section number of the broadcast segment i, determine whether the upstream broadcast segment ending at the upstream incoming section is a frequently congested broadcast segment or whether it is currently congested. Record the upstream incoming section number e that is not frequently congested and is not currently congested. uncongestion ;

[0031] Step 4-3: Based on the upstream cross-section number, determine whether the publishing segment ending at the upstream cross-section number of publishing segment i is a short path. If it is a short path, record the non-short path cross-section e. unshort e unshort ∈e uncongestion ;

[0032] Step 4-4: Numbering of upstream incoming sections based on non-short paths Based on the current traffic of broadcast segment i and the incoming traffic of broadcast segment i, filter out the routes with larger traffic, and record the upstream incoming section number e corresponding to the route with larger traffic. bigvol e bigvol ∈e unshort ;

[0033] Steps 4-5: Calculation of upstream cutoff section

[0034] The number of vehicles that the upstream publishing segment can accommodate is calculated based on the upstream publishing segment length, the number of lanes, and the average length of each vehicle:

[0035]

[0036] In the formula, Let e ​​be the upstream cross section e of the broadcast segment i, representing the maximum number of vehicles that the broadcast segment can accommodate. Let e ​​be the length of the upstream incoming section e of the publishing segment i;

[0037] Based on the upstream inbound section number e corresponding to the turn with high flow rate. bigvol To determine whether the flow does not flow downstream, i.e., whether there is pressure on the interception, the following conditions must be met:

[0038]

[0039] Then record the upstream cross-section number e that can be blocked without pressure. littleclosure e littleclosure ∈e bigvol ;

[0040] If e littleclosure If it is not empty, then the downstream set e littleclosurr Upstream interception can be performed at all cross-sections, i.e., the issue suggestion is in issue_suggest. i = 'Upstream interception', the suggested measure corresponds to the section number issue_sect i= e, e e littleclosure ;

[0041] Step 5, combine the single downstream dredging or upstream interception of service resources, or downstream dredging and upstream interception at the same time in real time, wherein, the downstream dredging is preferred, when the downstream dredging is not available, the upstream interception is selected according to the conditions.

[0042] Preferably, the step 3 comprises the following steps:

[0043] Step 301, set the warning number warn_count i to 0;

[0044] Step 302, if the issue section short path index issuesect_short_index i of the issue section i is greater than or equal to the short path overflow threshold short_issuesect_index_th, the short path has the risk of overflow, warn_count i = warn_count i + 1, go to the next step;

[0045] Otherwise, it is judged that the path has no overflow, issue_desc i = 'no', issue_suggest i = 'no', issue_flag i = 0, and go to the next moment to start from step 301 again, wherein:

[0046] issue_desc is the problem description;

[0047] issue_suggest is the problem suggestion;

[0048] issue_flag is the problem flag, 0 for no overflow, 1 for risk of overflow but no continuous overflow, 2 for overflow but has been warned, and 3 for short path overflow and warning.

[0049] Step 303, if the warning number warn_count i is greater than or equal to the warning number threshold warning_th, it is judged that the path has overflow, and go to the next step;

[0050] Otherwise, it is judged that the path has the risk of overflow but no continuous overflow, issue_desc i = 'there is a risk of overflow, but no continuous overflow', issue_suggest i = 'no', issue_flag i = 1, and go to the next moment to start from step 302 again;

[0051] Step 304, if the distance from the last alarm time is greater than the preset alarm interval, a path overflow alarm is performed, and issue_desc is output i = 'Short path congestion, risk of overflow', issue_flag i = 3, and step 4 is entered;

[0052] Otherwise, the path is overflowing, but the alarm has been given for a short time, and no repeated alarm is given, and issue_desc i = 'Short path congestion overflow, but has been alarmed', issue_suggest i = 'No', issue_flag i = 2, and the next time the process starts again from step 302.

[0053] Preferably, in step 401, the downstream traffic direction section numbers of the published segment i are represented by , wherein is the downstream left-turn traffic section number, is the downstream straight traffic section number, is the downstream right-turn traffic section number;

[0054] In step 402, the downstream traffic direction section numbers

[0055] Preferably, in step 404, if the traffic of the published segment i corresponding to the turning k of the downstream traffic direction section satisfies , wherein

[0056]

[0057] is the turning with greater traffic, wherein is the traffic of the current published segment i.

[0058] Preferably, in step 4-1, the upstream traffic direction section numbers of the published segment are represented by , wherein is the upstream left-turn traffic section number, is the upstream straight traffic section number, is the upstream right-turn traffic section number;

[0059] In step 4-2, the upstream traffic direction section numbers

[0060] Preferably, in step 4-4, the traffic of the section corresponding to the published segment i-1 of the published segment i satisfies

[0061]

[0062] Then, the turning is of large flow.

[0063] The application is based on city road network topology, release section flow, release section speed and other data, and alarm of short path overflow is carried out through short distance release section screening, short path overflow index calculation, short path overflow judgment and the like, and measures and suggestions of downstream dredging and upstream interception are given. The application is aimed at short distance road section research, needs to be completed on the basis of frequent congestion and real-time congestion judgment, and does not exist conflict with other digital traffic measures such as signal optimization and traffic channelization optimization. The fusion of historical congestion characteristics and real-time congestion characteristics of short distance release section is realized, and the downstream dredging or upstream interception measures for effectively relieving the short path overflow phenomenon are proposed according to the real-time congestion overflow characteristics, and the measures can effectively avoid the upstream and downstream spread of congestion overflow.

[0064] Compared with the prior art, the application has the following beneficial effects:

[0065] (1) The method is suitable for all city road paths of short release section, and has strong adaptability and accuracy;

[0066] (2) The short path overflow index is defined in the application, and the index is not only suitable for the judgment of short path overflow problem, but also suitable for the judgment of other congestion characteristics, such as business body surrounding entrance lock, continuous congestion, 300-500 meter release section congestion overflow judgment, downstream congestion overflow and the like;

[0067] (3) The application defines strict short path congestion overflow judgment and early warning threshold, which can effectively avoid false alarm caused by data fluctuation or repeated alarm caused by continuous congestion overflow;

[0068] (4) The downstream dredging measures and upstream interception measures proposed in the application are real-time judgments under current real-time data, so that the measures are more in line with actual traffic demand and more flexible;

[0069] (5) The downstream dredging and upstream interception measures proposed in the application design a strict anti-congestion aggravation mechanism, and the provided suggestions and measures can effectively relieve the short path congestion overflow problem. BRIEF DESCRIPTION OF DRAWINGS

[0070] Figure 1 It is a flow chart of short path problem diagnosis and measure recommendation. DETAILED DESCRIPTION

[0071] The application will be further described below in connection with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not to limit the scope of the application. Furthermore, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content of the application, and these equivalent forms also fall within the scope defined by the appended claims.

[0072] The application preliminarily explores the research and judgment of short path congestion overflow based on digital measures such as signal optimization and traffic organization optimization, proposes a targeted and flexible traffic management measure, and provides a general index calculation method for congestion classification, as shown in Figure 1 The specific steps include the following steps:

[0073] Step S-1: Frequent congestion release section screening and data extraction

[0074] Based on the history and real-time data table of the frequent congestion release section, the frequent congestion release section is screened, and the corresponding lane flow, turning flow, release section speed, release section length and other data are extracted. This step mainly analyzes the historical characteristics of the release section, aiming to make subsequent judgments and improvement suggestions for regular short path congestion overflow release sections, so as to alleviate the main congestion problem of urban roads.

[0075] Step S-2: Short distance release section screening. Based on the frequent congestion release section, the release section length is less than the short path distance threshold, that is:

[0076] issuesect_length i ≤short_issuesect_dis_th

[0077] issuesect_length i is the length of release section i, unit (meter), obtained from step S-1;

[0078] short_issuesect_dis_th is the short path distance threshold, unit (meter), default 200 meters.

[0079] Step S-3: Short path index calculation

[0080] This step mainly calculates the lane short path index and the release section short path index based on the flow, speed and release section length. The index is the main index for short path overflow judgment, which is obtained based on a large amount of data analysis and verification, and can effectively represent the congestion overflow characteristics. At the same time, this index can also be used for overflow judgment of road sections greater than the short path distance threshold of 100 meters and less than 500 meters, which is not the research content of the application and will not be expanded in detail.

[0081] Step S-3 specifically comprises the following steps:

[0082] Step S-3-1: Lane short path index calculation. Calculate the lane short path index according to the lane volume, lane speed, and the length of the release section:

[0083] lane_short_index ij = lane_volume ij / lane_speed ij / issuesect_length i * 10000

[0084] In the formula: lane_short_index is the short path index of lane j of release section i;

[0085] lane_volume ij is the volume of lane j of release section i, in units (vehicles), obtained from step S-1;

[0086] lane_speed ij is the speed of lane j of release section i, in units (meters / second), obtained from step S-1;

[0087] Step S-3-2: Release section short path index calculation. Based on the short path index of each lane of the release section, select the largest lane short path index as the release section short path index, which can effectively reduce the situation of high and low index caused by the red light period.

[0088] The calculation method of the short path index of the release section is as follows:

[0089]

[0090] In the formula: issuesect_short_index i is the short path index of release section i;

[0091] n i is the number of lanes of release section i.

[0092] Step S-4: Short path overflow judgment

[0093] Short path overflow needs to meet multiple consecutive periods exceeding the short path overflow threshold to be judged as short path overflow, which can effectively avoid false positives of short path overflow and improve the accuracy of congestion research.

[0094] Step S-4 specifically comprises the following steps:

[0095] Step S-4-1: Initialize the warning count to 0, i.e. warn_count i = 0.

[0096] Step S-4-2: Overflow risk judgment. If the publish segment short path indicator is greater than or equal to the short path overflow threshold, the short path has an overflow risk, the warning count is increased by 1, and step S-4-3 is entered, that is:

[0097] If issuesect_short_index i ≥ short_issuesect_index_th, then:

[0098] warn_count i = warn_count i + 1

[0099] Otherwise, it is judged that the path has no overflow, and issue_desc i = 'none', issue_suggest i = 'none', and issue_flag i = 0, and the next moment is entered to start from step S-4-1 again, wherein:

[0100] short_issuesct_index_th is the short path overflow threshold, and the default is 150;

[0101] issue_desc is the problem description;

[0102] issue_suggest is the problem suggestion;

[0103] issue_flag is the problem flag, 0 for no overflow, 1 for overflow risk but no continuous overflow, 2 for overflow but already warned, and 3 for short path overflow and warning.

[0104] Step S-4-3: Multi-period overflow risk judgment. The publish segment short path indicator is updated every 30s, and the warning count threshold warning_th is 4, that is, the path is determined to overflow only when it is judged to have an overflow risk for 4 consecutive times, and there is:

[0105] If the warning count is greater than or equal to the warning count threshold, that is,

[0106] warn_count i ≥ warning_th

[0107] It is judged that the path has an overflow, and step S-4-4 is entered;

[0108] Otherwise, it is judged that the path has an overflow risk but no continuous overflow, and issue_desc i = 'overflow risk but no continuous overflow', issue_suggesti = 'no', issue_flag i = 1, and go to the next time to start again from step S-4-2.

[0109] Step S-4-4: Alarm judgment. This step is mainly to avoid the occurrence of frequent alarm.

[0110] If the distance from the last alarm time is greater than the preset alarm interval, that is, it meets:

[0111] warn_time_interval = systime_time - last_warn_time

[0112] warn_time_interval ≥ short_interval_th

[0113] Then, the path overflow alarm is performed, and issue_desc is output i ='short path congestion, there is an overflow risk', issue_flag i = 3, and go to step S-5;

[0114] Otherwise, the path is overflowed, but the alarm has been given in a short time, and the alarm is not repeated, and issue_desc is output i ='short path congestion overflow, but has been alarmed', issue_suggest i = 'no', issue_flag i = 2, and go to the next time to start again from step S-4-2, wherein:

[0115] warn_time_interval is the distance from the last alarm time;

[0116] systime is the current system time;

[0117] last_warn_time is the last warning time, and the initial value is the time when the algorithm starts to calculate;

[0118] short_interval_th is the preset alarm interval, unit (second), and the default value is 30 min.

[0119] Due to the influence of the red light period, the speed and flow of the publishing section have certain volatility in a short time, although the maximum value of the lane short path index is selected as the short path index value of the publishing section, which reduces the volatility to a certain extent, but cannot avoid it completely. In order to reduce the misjudgment of congestion overflow, the application designs a strict short path overflow threshold, and designs a judgment standard that only when multiple continuous periods are congested does the short path congestion overflow is determined; in order to avoid information out of synchronization or repeated alarm in a short time and waste unnecessary police resources, the application sets a mechanism that does not repeat the alarm within 30 minutes; in order to give the most real-time optimization suggestion, the judgment of the measure suggestion is carried out only when the short path overflow alarm is carried out. In addition, the application marks each problem mark label in the overflow judgment process, which can be selected in real time and synchronized with the interface, which is helpful for early warning.

[0120] Step S-5: downstream dredging suggestion

[0121] The quick dredging measures that can be taken for the publishing section of the alarm include upstream interception and downstream dredging, which can be combined with single measures of service resources, or upstream and downstream measures can be simultaneously real-time, so as to quickly relieve road congestion. According to the management principle of giving priority to dredging, when the downstream cannot be dredged, the upstream interception is selected according to the conditions.

[0122] Step S-5 specifically includes the following steps:

[0123] Step S-5-1: extracting the downstream destination section of the publishing section

[0124] According to the topological relationship of the road network, the downstream traffic destination section number of the publishing section is extracted, generally the traffic flow of one publishing section goes to the downstream left, straight and right directions, and the corresponding sections can be represented by , respectively, wherein:

[0125] is the downstream left-turn traffic section;

[0126] is the downstream straight traffic section;

[0127] is the downstream right-turn traffic section;

[0128] Step S-5-2: filtering the downstream non-congestion publishing section

[0129] Based on the history and real-time data table of the frequently occurring congestion publishing section, whether the downstream publishing section with the downstream destination section as the terminal point is a frequently occurring congestion publishing section or is real-time congestion is judged according to the downstream destination section number of the publishing section i, and the downstream destination section number k of the frequently occurring congestion and the current non-congestion is recorded uncongestion , wherein,

[0130]

[0131] Step S-5-3: Downstream non-short-path publishing segment screening

[0132] Based on the non-congestion downstream publishing segment number k uncongestion , according to the downstream section number, it is judged whether the publishing segment with the downstream section number of the publishing segment i as the terminal is a short path:

[0133] If it is a short path, that is, it satisfies:

[0134]

[0135] Record the non-congestion, non-short-path downstream section number k unshort , wherein:

[0136] is the downstream publishing segment length corresponding to the downstream section e of the publishing segment i, unit (m);

[0137] k unshort ∈k uncongestion .

[0138] Step S-5-4: Large flow section screening

[0139] Based on the non-congestion, non-short-path downstream section number k unshort , based on the flow of the current publishing segment i and the turning flow of the publishing segment i, the turning with larger flow is screened, and the corresponding lane number is recorded, that is, if it satisfies:

[0140]

[0141] Record the downstream section number k corresponding to the turning with larger flow bigvol , wherein:

[0142] is the flow of the turning k corresponding to the downstream section of the publishing segment i;

[0143] is the flow of the current publishing segment i;

[0144] k bigvol ∈k unshort .

[0145] Step S-5-5: Downstream intercepting section calculation

[0146] Based on the downstream publishing segment length, the number of lanes, and the average length of each vehicle, the number of vehicles that can be accommodated by the publishing segment is calculated, and the calculation formula is as follows:

[0147]

[0148] In the formula: is the maximum number of vehicles that the publishing section corresponding to the section k downstream of the publishing section i can accommodate, unit (vehicles);

[0149] aver_vehicle_length is the average length of each vehicle, unit (meters), default 7 meters;

[0150] is the number of lanes of the publishing section corresponding to the section k downstream of the publishing section i.

[0151] Based on the large flow of the turning corresponding to the section number k downstream bigvol , it is judged whether the flow converges downstream has pressure, that is, if it meets:

[0152]

[0153] then record the section number k downstream that can converge without pressure littlesink , wherein k littlesink ∈k bigvol .

[0154] If k littlesink is not empty, then the sections in the downstream set k littlesink can be dredged, that is, the problem suggestion issue_suggest i = 'downstream dredging', and the section number corresponding to the suggestion measure issue_sect i =k, wherein k ∈ k littlesink .

[0155] Otherwise, go to the upstream interception judgment step, that is, step S-6.

[0156] Downstream dredging is better for the road section that is the bottleneck publishing section of the congestion publishing section, and the feature is that a large amount of traffic is gathered in a short time upstream, and cannot efficiently pass through the congestion publishing section or cannot accommodate all the traffic arriving from the upstream due to the short distance. In order to alleviate this feature, the present application comprehensively judges whether the downstream publishing section can be dredged from several aspects such as whether the downstream publishing section is congested frequently, whether it is congested, whether the downstream publishing section is too short, and whether the overflow traffic of the short path congestion publishing section is too large, and calculates the section number that can be dredged. This step can avoid dredging traffic to the downstream publishing section that is congested, which aggravates traffic congestion; secondly, for the publishing section that is easily congested and short in distance, in addition to the original traffic pressure, it avoids inputting additional traffic flow, which increases the overflow risk; thirdly, when the downstream publishing section is dredged, the flow direction with a large proportion of overflow traffic of the publishing section is selected, and the accommodation space of the downstream publishing section is calculated to ensure that when the part of the flow converges into the downstream publishing section, it will not cause overflow of the downstream publishing section, thereby ensuring the effectiveness and controllability of the measure.

[0157] Step S-6: Upstream cut-off suggestion.

[0158] Step S-6 specifically comprises the following steps:

[0159] Step S-6-1: Extract upstream coming direction section of publishing section

[0160] According to the topological relationship of the road network, the upstream traffic coming direction section number of the publishing section is extracted. Generally, the traffic of a publishing section is converged from the upstream left, straight, and right directions, and the corresponding sections can be represented by respectively, wherein:

[0161] represents the upstream left-turn traffic section;

[0162] represents the upstream straight traffic section;

[0163] represents the upstream right-turn traffic section.

[0164] Step S-6-2: Upstream non-congestion publishing section screening

[0165] Based on the historical and real-time data table of the frequently occurring congestion publishing section, according to the upstream coming direction section number of the publishing section i, it is judged whether the upstream publishing section with the upstream coming direction section as the terminal point is a frequently occurring congestion publishing section or is in real-time congestion. The upstream coming direction section number e of the frequently occurring congestion and the current non-congestion is recorded. uncongestion , wherein

[0166] Step S-6-3: Upstream short path publishing section screening

[0167] According to the upstream coming direction section number, it is judged whether the publishing section with the upstream section number of the publishing section i as the terminal point is a short path. If it is a short path, i.e., it satisfies:

[0168]

[0169] then the section e of the non-short path is recorded. unshort , wherein:

[0170] represents the length of the upstream publishing section corresponding to the upstream coming direction section e of the publishing section i, in units of (meters);

[0171] e unshort ∈e uncongestion .

[0172] Step S-6-4: Large flow section screening

[0173] Based on the upstream coming direction section number e of the non-short path 3nshort, based on the traffic of the current release section i, the traffic of the release section i is screened for larger traffic, that is, meet:

[0174]

[0175] Record the upstream direction section number e corresponding to the larger traffic diversion bigvol , wherein:

[0176] The upstream release section i-1 corresponding to the section diversion traffic of the release section i is represented, unit (vehicle);

[0177] e bigvol ∈e unshort .

[0178] Step S-6-5: Upstream interception section calculation

[0179] Based on the length of the upstream release section, the number of lanes, and the average length of each vehicle, the number of vehicles that can be accommodated by the upstream release section is calculated, and the calculation formula is as follows:

[0180]

[0181] In the formula, The length of the release section corresponding to the upstream direction section e of the release section i is represented, unit (meter).

[0182] Based on the upstream direction section number e corresponding to the larger traffic diversion bihvol , judge whether its traffic does not converge downstream, that is, whether the interception has pressure, if meet:

[0183]

[0184] Record the upstream direction section number e of the non-pressure interception littleclosure , wherein e littleclosure ∈e bigvol .

[0185] If e littleclosure is not empty, the sections in the downstream set e littleclosure can be intercepted upstream, that is, the problem suggestion issuw_suggest i = 'upstream interception', the section number corresponding to the recommended measures issue_sect i = e, wherein e ∈ e littleclosure . Otherwise, other management means need to be relied on to improve traffic congestion.

[0186] Upstream closure is a recommended suggestion when the downstream cannot be dredged. It performs well when the congestion release section extends to the upstream. This step can avoid stopping traffic flow to the upstream release section that is congested, exacerbating traffic congestion. For short release sections that are prone to congestion, it can avoid shortening the release time of traffic flow and increasing the risk of overflow. When the upstream is closed, the release section selects the flow direction with a large proportion of overflow traffic, and calculates the available space in the upstream release section to ensure that there is enough space in the upstream release section after the closure to prevent the spread of overflow.

Claims

1. A method for diagnosing and recommending measures for a short-path overflow problem of an urban road, characterized by, The method comprises the following steps: Step 1, screening to obtain a frequently congested publishing section, and extracting the lane flow, turning flow, publishing section speed and publishing section length corresponding to the publishing section, and then screening out a short-distance publishing section, wherein the publishing section length of the short-distance publishing section is less than a short-path distance threshold; Step 2, calculating a lane short-path index and a publishing section short-path index, wherein: The lane short path indicator for segment i lane j is denoted as lane_short_index ij Then, there is: lane_short_index ij = lane_volume ij / lane_speed ij / issuesect_length i *10000 where lane_volume ij is the volume for segment i lane j, lane_speed ij is the speed for segment i lane j; The issue section short path indicator for issue section i is denoted as issuesect_short_index i Then, there is: In the formula, n i is the number of lanes for publishing segment i; Step 3, if the issue section short path indicator issuesect_short_index of the issue section i is equal to 1 i If the number of consecutive periods exceeds the short path overflow threshold, a path overflow alarm is generated. Step 4, obtaining a downstream dredging suggestion and an upstream interception suggestion, wherein: The downstream dredging suggestion is obtained by the following steps: Step 401, extracting downstream traffic direction section numbers of the publishing section according to a road network topological relationship; Step 402, based on the frequently occurring congestion release section history and real-time data table, according to the downstream destination section number of the release section i, judge whether the downstream release section with the downstream destination section as the terminal point is a frequently occurring congestion release section or whether it is real-time congestion, record the downstream destination section number k which is not currently congested and is a frequently occurring congestion uncongestion ; Step 403, based on the non-congestion downstream publishing segment number k uncongestion , according to the downstream section number, judge whether the publishing segment with the downstream section number of the publishing segment i as the end point is a short path, if it is a short path, record the non-congestion, non-short path downstream section number k unshort , k unshort ∈k uncongestion ; Step 404, based on non-congestion, non-short path downstream section number k unshort , based on the traffic of the current release section i, the diversion traffic of the release section i, the traffic of the larger diversion is screened, and the corresponding downstream section number k is recorded bigvol , k bigvol ∈k unshort ; Step 405, calculating a number of vehicles that can be accommodated in the publishing section based on a downstream publishing section length, a number of lanes and an average length of each vehicle: In the formula, is the maximum number of vehicles that can be accommodated in the publication section corresponding to the section k downstream of the publication section i, and aver_vehicle_length is the average length of each vehicle, is the number of lanes in the publication section corresponding to the section k downstream of the publication section i. Based on the large flow of the corresponding downstream diversion section number k bigvol , determine whether the flow into the downstream has pressure, when meet: then record the downstream section number k to which the flow can be merged without pressure littlesink , k littlesink ∈k bigvol ; If k littlesink is not empty, then the cross-sections in the downstream set k littlesink can be dredged, that is, the problem suggestion issue_suggest i = ′downstream dredging′, and the cross-section number corresponding to the suggestion measure issue_sect i = k, where k ∈ k littlesink . The upstream interception suggestion is obtained by the following steps: Step 4-1, extracting upstream traffic direction section numbers of the publishing section according to a road network topological relationship Step 4-2, according to the upstream of the publishing section i, determine whether the upstream publishing section which is the end point of the upstream coming section is a common congestion publishing section or whether it is a real-time congestion, and record the upstream coming section number e which is a common congestion and not currently congested uncongestion ; Step 4-3, according to the upstream section number, judge whether the publishing section with the end point of the upstream section number of publishing section i is a short path, if it is a short path, record the non-short path section e unshort , e unshort ∈e uncongestion ; Step 4-4, based on non-short path upstream to the section number e unshort , based on the traffic of the current publishing section i, the traffic of the publishing section i, the traffic of the larger diversion is screened, and the upstream to section number e corresponding to the larger diversion is recorded bigvol , e bigvol ∈e unshort ; Step 4-5: upstream interception section calculation Calculating a number of vehicles that can be accommodated in the upstream publishing section based on an upstream publishing section length, a number of lanes and an average length of each vehicle: In the formula, is the maximum number of vehicles that can be accommodated by the publication section corresponding to the upstream-to-section e of the publication section i, is the length of the publication section corresponding to the upstream-to-section e of the publication section i. Based on the large flow of the corresponding upstream to the upstream section number e bigvol , to determine whether the flow does not converge downstream, that is, whether the interception has pressure, when the following conditions are met: then record the upstream cross-section number e where the flow can be intercepted without pressure littleclosure , e littleclosure ∈e bigvol ; If e littleclosure is not empty, then all cross sections in the downstream set e littleclosure can be intercepted from the upstream, i.e. the problem suggestion issue_suggest i = ′upstream interception′, and the corresponding cross section number of the suggestion measure issue_sect i = e, e ∈ e littleclosure ; Step 5, combining the downstream dredging or the upstream interception of the single service resource, or the downstream dredging and the upstream interception at the same time in real time, wherein the downstream dredging is preferentially selected, when the downstream cannot be dredged, the upstream interception is selected according to conditions.

2. The urban road short path overflow problem diagnosis and measure recommendation method of claim 1, wherein, The step 3 comprises the following steps: Step 301, initialize the warning number warn_count i initialize to 0; Step 302, if the issue section short path indicator of the issue section i issuesect_short_index i is greater than or equal to the short path overflow threshold short_issuesect_index_th, then the short path is at risk of overflow, warn_count i = warn_count i + 1, go to next step; Otherwise, determine that the path is not overflowed, output issue_desc i = 'none', issue_suggest i = 'none', issue_flag j = 0, and proceed to the next time instant, starting again from step 301. issue_desc is a problem description; issue_suggest is a problem suggestion; issue_flag is a problem flag, 0 is no overflow, 1 is overflow risk but no continuous overflow, 2 is overflow but has reported alarm, and 3 is short-path overflow and alarm. Step 303, if the number of pre-alarm times warn_count i If the number of pre-alarm times is greater than or equal to the threshold value of pre-alarm times warning_th, it is judged that the path is overflowed, and the next step is entered. Otherwise, determine that there is a risk of overflow, but no continuous overflow, and output issue_desc i = 'Risk of overflow, but no continuous overflow', issue_suggest i = 'No', issue_flag i = 1, and proceed to the next time instant, starting again from step 302. Step 304, if the distance from the last alarm time is greater than the preset alarm interval, the path overflow alarm is performed, and issue_desc is output i = 'Short path congestion, risk of overflow', issue_flag i = 3, and step 4 is entered. Otherwise, the path is overflowed, but the alarm has been issued in a short time, no longer repeated alarm, output issue_desc i = 'Short path congestion overflow, but has been issued', issue_suggest i = 'No', issue_flag i = 2, and enters the next time to start again from step 302.

3. The urban road short path overflow problem diagnosis and measure recommendation method of claim 1, wherein, In step 401, the downstream vehicle flow of the released section i is represented by , where, is the downstream left-turn vehicle flow section number, is the downstream straight vehicle flow section number, is the downstream right-turn vehicle flow section number; In step 402, the downstream destination section number is assigned 4. The urban road short path overflow problem diagnosis and measure recommendation method of claim 1, wherein, In step 404, if the flow of the diversion k corresponding to the downstream destination section of the release section i satisfies the following: is the flow of the current release segment i, wherein is the flow of the current release segment i, wherein 5. The urban road short path overflow problem diagnosis and measure recommendation method of claim 1, wherein, In Step 4-1, the upstream traffic on the release segment to the cross section numbers are represented by wherein, represents the upstream left-turn traffic cross section number, represents the upstream straight traffic cross section number, represents the upstream right-turn traffic cross section number; Step 4-2 in the upstream direction 6. The urban road short path overflow problem diagnosis and measure recommendation method of claim 1, wherein, In step 4-4, the section turning flow corresponding to the upstream publishing section i-1 of the publishing section i satisfies: It is a larger turning flow.

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