Urban road frequent traffic jam relieving method

Abstract

The invention discloses a method for relieving frequent traffic congestion of an urban road. The method comprises the following steps: 1) constructing an induction factor system of the frequent traffic congestion; 2) obtaining various induction factor parameter values of the induction factor system of the frequent traffic jam in the step 1); 3) determining a common traffic jam road network; 4) inputting the various induction factor parameter values in the step 2) into the frequent traffic jam road network in the step 3), and constructing a frequent traffic jam road network defibering scheme; and 5) establishing a simulation model according to the frequent traffic jam road network defibering scheme in the step 4), and verifying the effectiveness of the defibering scheme. The invention further provides electronic equipment and a computer readable storage medium. According to the invention, through quantitative analysis of induction factor parameters of frequent traffic congestion, a traffic defibering scheme is constructed so as to relieve the road congestion condition.

Description

Technical Field

[0001] The invention belongs to the field of transportation, and in particular relates to a method for alleviating traffic congestion that often occurs on urban roads. Background Art

[0002] As cities continue to develop, the problem of road traffic congestion has become increasingly prominent. Some urban roads are often congested during peak hours in the morning and evening, and the road traffic efficiency is low, which reduces the happiness of traveling. At the same time, frequent traffic congestion is often accompanied by traffic overflow, and traffic congestion spreads to other roads or even the entire road network. Existing road relief methods usually rely on experience and are based on qualitative perspectives. It is difficult to find the real congestion points, resulting in limited road relief.

[0003] Therefore, we urgently need a new road decongestion method to alleviate road congestion. Summary of the invention

[0004] The main purpose of the present invention is to provide a method for alleviating frequent traffic congestion on urban roads. The method quantitatively analyzes the parameters of inducing factors of frequent traffic congestion and constructs a traffic relief plan to alleviate road congestion.

[0005] The technical solution adopted by the present invention is:

[0006] A method for alleviating frequent traffic congestion on urban roads, comprising the following steps:

[0007] 1) Establish a system of factors that cause frequent traffic congestion;

[0008] 2) obtaining the parameter values ​​of various inducing factors of the inducing factor system of frequent traffic congestion in step 1);

[0009] 3) Identify the road network with frequent traffic congestion;

[0010] 4) Inputting the parameter values ​​of various inducing factors in step 2) into the road network with frequent traffic congestion in step 3) to construct a solution for alleviating frequent traffic congestion on the road network;

[0011] 5) Establish a simulation model based on the road network relief plan for frequent traffic congestion in step 4) to verify the effectiveness of the relief plan.

[0012] The present invention also provides an electronic device, comprising:

[0013] a memory for storing executable computer programs;

[0014] The processor is used to implement a method for alleviating common traffic congestion on urban roads when executing an executable computer program stored in the memory.

[0015] The present invention also provides a computer-readable storage medium storing a computer program for implementing a method for alleviating common traffic congestion on urban roads when executed by a processor.

[0016] The beneficial effects of the present invention are:

[0017] Analyze the frequent traffic congestion on urban roads, establish a multi-level analysis system based on the actual status of road traffic congestion, quantitatively analyze the indicators of each system, build a traffic relief plan, improve the management efficiency of frequent traffic congestion on urban roads, and provide reference for urban traffic managers;

[0018] The present invention comprehensively considers the factors causing traffic congestion from the macro, meso and micro levels, constructs a system of factors causing frequent traffic congestion at three general levels, namely the road network level, the road section level and the node level, and 12 index levels, and proposes a method for obtaining parameters at the 12 index levels, thereby improving the effectiveness and comprehensiveness of the analysis of frequent traffic congestion.

[0019] The road network with frequent traffic congestion is clarified, and the relief plans for each road network with frequent traffic congestion are proposed to provide effective decision-making solutions for solving frequent traffic congestion and effectively alleviate road congestion;

[0020] The present invention uses the software VISSIM to analyze and verify the effectiveness of various common traffic congestion relief plans, and proposes modeling content and evaluation type indicators for various relief plans, which can effectively verify the effectiveness of the relief plans. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A flowchart of a method for alleviating common traffic congestion on urban roads;

[0023] Figure 2 This is a schematic diagram of the inducing factor system of frequent traffic congestion;

[0024] Figure 3 Schematic diagram of the process for determining the road network with frequent traffic congestion;

[0025] Figure 4 A flow chart showing the establishment of a simulation model for a road network solution for frequent traffic congestion and the verification of the effectiveness of the solution. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] Example 1

[0028] like Figure 1 As shown, a method for alleviating common traffic congestion on urban roads includes the following steps: constructing a system of inducing factors of common traffic congestion → obtaining parameter values ​​of various inducing factors → determining a road network of common traffic congestion → constructing a solution for the road network of common traffic congestion → establishing a simulation model to verify the effectiveness of the solution.

[0029] Step 1: Construct a system of factors that cause frequent traffic congestion, such as Figure 2 As shown, the inducing factor system includes 3 general levels and 12 indicator levels.

[0030] Among them, the inducing factor system of frequent traffic congestion includes three general levels, namely, the traffic network layer, the traffic section layer, and the traffic node layer. The traffic network layer includes three indicator layers, including road network density, transit traffic flow ratio, and arrival-departure traffic flow ratio. The traffic section layer includes five indicator layers, including the matching degree between road cross-section scale and traffic flow, motor vehicle traffic organization efficiency, public transportation organization efficiency, slow traffic organization efficiency, and traffic flow imbalance coefficient. The traffic node layer includes four indicator layers, including the number of lanes matching upstream and downstream of the node, node spacing, node traffic flow organization smoothness, and node traffic signal control efficiency.

[0031] Step 2: Obtain the parameter values ​​of various inducing factors. The parameters of the 12 indicator layers are obtained as follows:

[0032] (1) The parameter values ​​of each indicator layer of the traffic network layer are obtained as follows:

[0033] ①Road network density Where D is the road network density, in km / km 2 ; l n is the length of a certain grade of road, in meters; A is the area of ​​the main road adjacent to a certain grade of road, in kilometers 2 ;

[0034] ② Transit traffic flow ratio Among them, V T is the transit traffic flow ratio; V t is the transit traffic flow, in pcu; V is the total traffic flow, in pcu;

[0035] ③Ratio of arrival and departure traffic flow Among them, VA V is the arrival and departure traffic flow ratio; a is the arrival and departure traffic flow, in pcu; V is the total traffic flow, in pcu;

[0036] (2) The parameter values ​​of each indicator layer of the traffic section layer are obtained as follows:

[0037] ① Matching degree between road cross-section scale and traffic flow Among them, M is the matching degree between the road cross-section scale and traffic flow; Q is the hourly traffic flow during peak hours, in pcu / h; N is the number of lanes in the cross section; N p is the possible traffic capacity of a road, in pcu / h;

[0038] ②Motor vehicle traffic organization efficiency Among them, E M is the traffic organization efficiency of motor vehicles; L is the length of the road section, in km; t M is the travel time of motor vehicles on the road section, in hours; S M The design speed of motor vehicles on the road section, in km / h;

[0039] ③ Public transportation organization efficiency Among them, E T is the efficiency of public transportation organization; L is the length of the road section, in km; t T is the travel time of motor vehicles on the road section, in hours; S T Design speed for public transport on the road section, in km / h;

[0040] ④ Slow traffic organization efficiency Among them, E P is the efficiency of slow traffic organization; L is the length of the road section, in km; t P is the travel time of slow traffic on the road section, in h; S T Design speed for slow traffic, in km / h;

[0041] ⑤ Traffic flow imbalance coefficient Where P is the traffic flow imbalance coefficient; R a is the peak traffic flow on one side of the road section, in pcu / h; R b is the peak traffic flow of the section on the other side of the road, in pcu / h;

[0042] (3) The parameter values ​​of each indicator layer of the traffic node layer are obtained as follows:

[0043] ① Number of node upstream and downstream lane matches:

[0044] S L =SL1 -S L2 ;

[0045] S S =S S1 -S S2 ;

[0046] S R =S R1 -S R2 ;

[0047] Among them, S L S is the number of matching upstream and downstream lanes for a left turn at the node; L1 S is the number of left-turn upstream exits; L2 S is the number of left-turn downstream entrances; S S is the number of matching lanes for the node’s straight upstream and downstream lanes; S1 S is the number of straight upstream exits; S2 is the number of straight downstream inlet channels; S R S is the number of matching lanes for the node’s right turn upstream and downstream; R1 S is the number of right-turn upstream exits; R2 is the number of right-turn downstream entrance roads;

[0048] ②Node spacing R = r1-r2; where R is the spacing between two cross nodes, in m; r1 is cross node 1; r2 is cross node 2;

[0049] ③ Smoothness of node traffic flow organization Among them, N is the smoothness of node traffic flow organization; n is the number of node traffic conflict points; t n is the travel time of the nth traffic conflict point in the peak hour, in h; T is the theoretical travel time of the traffic flow at the conflict point in the peak hour, in h;

[0050] ④ Traffic signal control efficiency at nodes Among them, E C Control the traffic efficiency of node traffic signals; Q C Peak hour traffic flow at an intersection in a certain direction, pcu / h; λ i is the green signal ratio of the signal phase of the i-th import lane; S i is the saturation flow rate of the i lane group or i approach, in pcu / green light hour.

[0051] Step 3: Determine the road network with frequent traffic congestion, such as Figure 3 As shown: Preliminarily determine the roads with frequent traffic congestion → obtain the traffic volume of the intersecting roads with frequent traffic congestion → analyze the congestion characteristics of the intersecting roads → determine the roads that affect frequent traffic congestion → determine the road network with frequent traffic congestion. Specifically:

[0052] First, analyze the sections or nodes of a certain road. During the morning and evening peak hours, the time when the road service level is greater than 0.9 is higher than 50% of its morning and evening peak hours, and it is initially determined to be a road with frequent traffic congestion;

[0053] Secondly, for the roads affected by frequent traffic congestion overflow (and their intersecting roads), the peak hour traffic volume in the morning and evening for three consecutive days was obtained, and the average value was taken as the peak hour traffic volume of the intersecting roads;

[0054] Secondly, the service level and peak congestion duration of roads (intersecting roads) affected by frequent traffic congestion overflow are taken as the congestion characteristics of the intersecting roads;

[0055] Then, if the service level of the road affected by overflow of frequent traffic congestion (its intersecting roads) is greater than 0.9 for more than 30% of its morning and evening peak hours, it is the affected road of frequent traffic congestion;

[0056] Finally, the initially determined roads with frequent traffic congestion and the roads affected by frequent traffic congestion are connected to form a road network with frequent traffic congestion.

[0057] Step 4: Construct a road network solution for frequent traffic congestion, which includes the following steps:

[0058] (1) Construct a balanced regional road network based on the parameter values ​​of each indicator layer of the traffic road network layer;

[0059] ① When the congested road level is urban expressway, trunk road, secondary trunk road, branch road, the corresponding road network density D should be 0.4~0.5km / km 2 , 0.8~1.2km / km 2 1.2~1.4km / km 2 , 3~4km / km 2 ; When the road network density D is not within the corresponding value range, the road network skeleton can be improved and the road network structure density can be adjusted;

[0060] For example, when the road network density of main, secondary and branch roads in a certain urban area is good and there is no expressway, the expressway network density is 0. By transforming the main roads of a certain city into expressways and building viaducts, the expressway network density after the transformation is 0.43km / km. 2 , meeting the urban road network density construction standards, can realize the rapid transit of local traffic flow, and alleviate the pressure of transit traffic flow on urban internal traffic.

[0061] ② When the transit traffic flow ratio Vt> the departure traffic flow ratio V A , by diverting transit traffic, establishing a freight transportation network, and implementing regional traffic restrictions;

[0062] Among them, the transit traffic flow is diverted: regional ring line transit and regional internal straight line transit.

[0063] Establish a freight transportation network: ban freight at different time periods, ban freight at different road sections, and separate passenger and freight roads.

[0064] Implement regional traffic restrictions: special lanes are restricted; motor vehicles, non-motor vehicles and pedestrians in the area are guided and restricted; traffic is restricted when there are large-scale mass activities or large-scale construction;

[0065] ③ When the arrival and departure traffic volume ratio is V A >0.8, a micro-circulation traffic network, a one-way traffic network, a left-no-turn traffic network, and a public transportation network can be constructed in a road network with frequent traffic congestion;

[0066] Among them, building a micro-circulation traffic network: based on the traffic demand and diversion demand, new branch roads are built, dead-end roads are opened, branch roads are recovered, branch roads are renovated, entrances and exits are adjusted, motor vehicles are prohibited from turning left or right at intersections, and motor vehicles are organized to travel in one direction to build a micro-circulation road network;

[0067] Construct one-way traffic network: according to the traffic flow characteristics of different road networks, fixed one-way traffic, time-line one-way traffic, reversible one-way traffic, and one-way traffic based on vehicle type characteristics can be formed;

[0068] Construct a left turn-free traffic network: For roads affected by frequent traffic congestion and the regional road network composed of their connected roads, left turn-free restrictions can be implemented first to ensure the accessibility of traffic to and from the destination;

[0069] Build a public transportation network: Build a public transportation network on urban expressways and trunk roads;

[0070] (2) Construct an orderly and smooth road section based on the parameter values ​​of each indicator layer of the traffic section layer:

[0071] ① When the road cross-section scale and traffic flow matching degree M < 0.6, or M > 0.9, the number of lane scales of the road section can be adjusted and optimized, including increasing or decreasing the number of lane scales; for example: when M > 0.9, the number of lane scales can be increased; when M < 0.6, the number of lane scales can be reduced;

[0072] ② When the traffic organization efficiency of motor vehicles is E M <0.6, Public transportation organization efficiency E T <0.6, Slow traffic organization efficiency E P <0.6, the following can be done: lane width optimization, road section entrance and exit optimization, road cross section optimization, central median opening optimization, bus stop location and form optimization, road section pedestrian crossing location and form optimization, main and auxiliary entrance and exit location and form optimization;

[0073] ③When the traffic flow imbalance coefficient P>0.2, a tidal lane can be set up on the road section.

[0074] (3) Construct safe and efficient nodes based on the parameter values ​​of each indicator layer of the traffic node layer;

[0075] ① When the node turns left, the number of upstream and downstream lanes matching S L <0, the number of matching lanes of the node's straight upstream and downstream lanes S S <0 or the number of matching lanes of the node right turn upstream and downstream S R <0, adjust the number of entrance and exit lanes of the node intersection, increase the number of lanes of the upstream entrance lane of the node intersection or reduce the number of lanes of the downstream exit lane of the node intersection, so that S L , S S , S R The values ​​of are ≥ 0;

[0076] ② When the road grade in the road network with frequent traffic congestion is an urban trunk road, and the distance between two intersections R is less than 600m; when the grade is an urban secondary road, and the distance between two intersections is less than 300m, the intersections should be controlled and adjusted to: prohibit left and right entry and exit at grade-separated intersections and traffic light-controlled intersections;

[0077] ③ When the smoothness of node traffic flow organization N is less than 0.7, the node intersection entrance channelization, exit channelization, and intersection channelization can be optimized;

[0078] Among them, the entrance channelization includes the optimization of the number of lanes, lane width, functional division, stop line position, gradient section length, widening section length, left-turn lane, right-turn lane, and U-turn lane;

[0079] Exit channelization includes optimization of lane number, lane width, functional division, gradient section length, and widening section length;

[0080] Channelization within intersections includes optimization of diversion lines and diversion islands;

[0081] ④ When the node traffic signal controls the traffic efficiency E C When it is less than 0.7, the traffic control method, traffic signal phase and traffic signal timing can be optimized and adjusted.

[0082] Step 5: Establish a simulation model to verify the effectiveness of the relief plan, such as Figure 4 As shown; specifically:

[0083] Firstly, a preliminary simulation model was constructed using the simulation software VISSIM. This mainly included: drawing a CAD road network with frequent traffic congestion as the base map of the simulation model; defining traffic attributes, setting input driving behavior parameters, expected speed distribution, parking time distribution, etc.; defining road network attributes, inputting current traffic flow and current traffic control methods based on actual traffic flow data, adding road sections and connectors, and defining vehicle input and path decisions.

[0084] Secondly, establish simulation models for various types of relief plans; based on the established preliminary model, establish simulation models for various types of relief plans according to the traffic characteristics of relief plans for road networks with common traffic congestion.

[0085] (1) The simulation model of each relief scheme for the balanced regional road network is established as follows:

[0086] ① Improve the road network skeleton: In the CAD of the road network with frequent traffic congestion, adjust the simulation model base map according to the road network density adjustment plan;

[0087] ② To divert transit traffic, establish a freight transportation network, and implement regional traffic restrictions: adjust vehicle behavior parameters, adjust vehicle path decisions, adjust vehicle type ratios, and set traffic restriction rules.

[0088] ③ Construct a micro-circulation traffic network, a one-way traffic network, a no-left-turn traffic network, and a public transportation network: adjust vehicle driving path decisions, set traffic restriction rules, and set bus route paths.

[0089] (2) The simulation model of each relief plan for orderly and unobstructed road sections is established as follows:

[0090] ① Increase or decrease the number of lanes: adjust the number of lanes in the road section of the simulation model base map, and adjust the vehicle path decision accordingly;

[0091] ② Lane width optimization, road section entrance and exit optimization, road cross section optimization, central median opening optimization, bus stop location and form optimization, pedestrian crossing location and form optimization, main and auxiliary entrance and exit location and form optimization: adjust the attribute parameters (lane width, length) of each section in the road network, set the priority rules for the main and auxiliary entrance and exit interweaving areas, set road priority, define pedestrian attributes, define bus attributes, set bus stops, and set pedestrian crossings on the road section;

[0092] ③ Setting up tidal lanes on road sections: adjusting vehicle input and adjusting vehicle path decisions.

[0093] (3) The simulation model of each decongestion solution for efficient operation nodes is established as follows:

[0094] ① Adjustment of the number of lane matches between upstream and downstream nodes: Adjustment of vehicle path decision;

[0095] ② Intersection: set the road section attributes and adjust the height; No Left Turn at Traffic Light Intersection: set the turning rules and adjust the vehicle path decision; Right In and Right Out: set the turning rules and adjust the vehicle path decision;

[0096] ③ Channelization of node intersection entrance roads, exit roads, and intersections: set up deceleration zones, set up deceleration zones in entrance roads and intersection areas, set up priority rules and conflict areas, and set road priority.

[0097] ④ Adjust traffic control methods, traffic signal phases, and traffic signal timing: set traffic light control plans, set signal parameters, set pedestrian path decisions, and set pedestrian crossing signal controls.

[0098] Finally, set the evaluation type, run the simulation and output the results to verify the effectiveness of the solution.

[0099] At the road network level, the evaluation type indicator is set as travel time; at the road section level, the evaluation type indicator is set as operating speed; at the node level, the evaluation type indicator is set as delay time and queue length.

[0100] Example 2

[0101] An electronic device, comprising:

[0102] a memory for storing executable computer programs;

[0103] The processor is used to implement the method for alleviating common traffic congestion on urban roads in the embodiment when executing the executable computer program stored in the memory.

[0104] Example 3

[0105] A computer-readable storage medium stores a computer program for implementing the method for alleviating common traffic congestion on urban roads in Example 1 when executed by a processor.

[0106] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0107] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A method for alleviating frequent traffic congestion on urban roads, characterized in that: The steps include: 1) Establish a system of factors that cause frequent traffic congestion; 2) obtaining the parameter values ​​of various inducing factors of the inducing factor system of frequent traffic congestion in step 1); 3) Identify the road network with frequent traffic congestion; 4) Inputting the parameter values ​​of various inducing factors in step 2) into the road network with frequent traffic congestion in step 3) to construct a solution for alleviating frequent traffic congestion on the road network; 5) Establish a simulation model based on the road network relief plan for frequent traffic congestion in step 4) to verify the effectiveness of the relief plan.

2. The method for alleviating frequent traffic congestion on urban roads according to claim 1, characterized in that: The inducing factor system of frequent traffic congestion in step 1) includes three general levels: traffic network layer, traffic section layer, and traffic node layer, among which: The traffic network layer includes three indicator layers: road network density, transit traffic flow ratio, and arrival-departure traffic flow ratio; The traffic section layer includes five indicator layers: the matching degree between road cross-section scale and traffic flow, the efficiency of motor vehicle traffic organization, the efficiency of public transportation organization, the efficiency of slow traffic organization, and the traffic flow imbalance coefficient. The traffic node layer includes four indicator layers: the number of upstream and downstream lane matches, node spacing, smoothness of node traffic flow organization, and traffic signal control efficiency of nodes.

3. The method for alleviating frequent traffic congestion on urban roads according to claim 2, characterized in that: The calculation formulas for the parameter values ​​of various inducing factors in the inducing factor system of frequent traffic congestion are as follows: The calculation formulas for the parameter values ​​of each indicator layer of the traffic network layer are as follows: (1) Road network density Where: D is the road network density, unit is km / km 2 ; l n is the length of a certain grade of road, in meters; A is the area of ​​the main road adjacent to a certain grade of road, in kilometers 2 ; (2) Transit traffic flow ratio Where: V T is the transit traffic flow ratio; V t is the transit traffic flow, in pcu; V is the total traffic flow, in pcu; (3) Arrival and departure traffic flow ratio Where: V A V is the arrival and departure traffic flow ratio; a is the arrival and departure traffic flow, in pcu; V is the total traffic flow, in pcu; The calculation formulas for the parameter values ​​of each indicator layer of the traffic section layer are as follows: (1) Matching degree between road cross-section scale and traffic flow Where: M is the matching degree between the road cross-section scale and traffic flow; Q is the hourly traffic flow during peak hours, in pcu / h; N is the number of lanes in the cross section; N p is the possible traffic capacity of a road, in pcu / h; (2) Efficiency of motor vehicle traffic organization Where: E M is the traffic organization efficiency of motor vehicles; L is the length of the road section, in km; t M is the travel time of motor vehicles on the road section, in hours; S M The design speed of motor vehicles on the road section, in km / h; (3) Public transport organization efficiency Where: E T is the efficiency of public transportation organization; L is the length of the road section, in km; t T is the travel time of motor vehicles on the road section, in hours; S T Design speed for public transport on the road section, in km / h; (4) Slow traffic organization efficiency Where: E P is the efficiency of slow traffic organization; L is the length of the road section, in km; t P is the travel time of slow traffic on the road section, in h; S T Design speed for slow traffic, in km / h; (5) Traffic flow imbalance coefficient Where: P is the traffic flow imbalance coefficient; R a is the peak traffic flow on one side of the road section, in pcu / h; R b is the peak traffic flow of the section on the other side of the road, in pcu / h; The calculation formulas for the parameter values ​​of each indicator layer of the traffic node layer are as follows: (1) The calculation formula for the number of matching lanes at a node is as follows: S L =S L1 -S L2 ; S S =S S1 -S S2 ; S R =S R1 -S R2 ; Where: S L S is the number of matching upstream and downstream lanes for a left turn at the node; L1 S is the number of left-turn upstream exits; L2 S is the number of left-turn downstream entrances; S S is the number of matching lanes for the node’s straight upstream and downstream lanes; S1 S is the number of straight upstream exits; S2 is the number of straight downstream inlet channels; S R S is the number of matching lanes for the node’s right turn upstream and downstream; R1 S is the number of right-turn upstream exits; R2 is the number of right-turn downstream entrance roads; (2) Node spacing R = r1-r2 Where: R is the distance between two cross nodes, in meters; r1 is cross node 1; r2 is cross node 2; (3) Node traffic flow organization smoothness N Where: N is the smoothness of node traffic flow organization; n is the number of node traffic conflict points; t n is the travel time of the nth traffic conflict point in the peak hour, in h; T is the theoretical travel time of the traffic flow at the conflict point in the peak hour, in h; (4) Traffic efficiency of node traffic signal control Where: E C Control the traffic efficiency of node traffic signals; Q C Peak hour traffic flow at an intersection in a certain direction, in pcu / h; λ i is the green signal ratio of the signal phase of the i-th import lane; S i is the saturation flow rate of the i lane group or i approach, in pcu / green light hour.

4. The method for alleviating frequent traffic congestion on urban roads according to claim 1, characterized in that: Step 3) The steps for determining the road network with frequent traffic congestion are: Preliminarily determine the roads with frequent traffic congestion → obtain the traffic volume of intersecting roads with frequent traffic congestion → analyze the congestion characteristics of intersecting roads → determine the roads affected by frequent traffic congestion → determine the road network with frequent traffic congestion.

5. The method for alleviating frequent traffic congestion on urban roads according to claim 4, characterized in that: The method for preliminarily determining roads with frequent traffic congestion is as follows: a road section or node is preliminarily determined to be a road with frequent traffic congestion if the time when the road service level is greater than 0.9 during the morning and evening peak hours is greater than 50% of the time during the morning and evening peak hours. The method for obtaining the traffic volume of intersecting roads with frequent traffic congestion is as follows: the intersecting roads with frequent traffic congestion are affected by the inflow and outflow of frequent traffic congestion. It is necessary to obtain the hourly traffic volume of the intersecting roads during the morning and evening peak hours for 3 days continuously, and take the average value as the peak traffic volume of the intersecting roads; The method for analyzing the congestion characteristics of intersecting roads is as follows: the traffic flow overflow of the frequently congested road connects to the road, and its congestion characteristics are the road service level and the congestion duration during peak hours; the congestion characteristics of the intersecting roads are considered in sections, that is, the sections between the adjacent road nodes of the frequently congested road are analyzed; The method for determining the roads affected by frequent traffic congestion is as follows: if the time when the road service level of the road section is greater than 0.9 is greater than 30% of its morning and evening peak time periods, it is the road affected by frequent traffic congestion; the road service level of the road section is the ratio of the traffic volume of the intersecting road to the traffic capacity of the intersecting road; The road network with frequent traffic congestion is a road network consisting of preliminarily determined frequent traffic congestion roads and the connection combinations of roads influencing frequent traffic congestion.

6. The method for alleviating frequent traffic congestion on urban roads according to claim 1, characterized in that: The road network solution for frequent traffic congestion in step 4) includes a frequent traffic congestion relief system at three levels: balanced regional road network, orderly and unobstructed road sections, and safe and efficient nodes. The following are the steps for constructing the three frequent traffic congestion relief systems: According to the parameter values ​​of each indicator layer of the traffic network layer, a balanced regional road network is constructed: When the congested road level is urban expressway, trunk road, secondary trunk road, branch road, the corresponding road network density D should be 0.4-0.5km / km2, 0.8-1.2km / km2, 1.2-1.4km / km2, 3-4km / km2; when the road network density D is not within the corresponding value range, the road network skeleton should be improved and the road network structure density should be adjusted; When the transit traffic ratio Vt> the arrival and departure traffic ratio VA, control and divert the transit traffic flow, establish a freight transportation network, and implement regional traffic restrictions; Among them, divert transit traffic flow: regional loop transit, regional internal straight line transit; Establish a freight transportation network: ban freight at different time periods, ban freight in different road sections, and separate passenger and freight roads; Implement regional traffic restrictions: special lanes are restricted; motor vehicles, non-motor vehicles and pedestrians in the area are guided and restricted; traffic is restricted when there are large-scale mass activities or large-scale construction; When the arrival-departure traffic volume ratio VA>0.8, a micro-circulation traffic network, a one-way traffic network, a left-no-left traffic network, and a public transportation network are constructed in the road network with frequent traffic congestion; Among them, the construction of a micro-circulation traffic network: based on the traffic demand and diversion demand, new branch roads are built, dead-end roads are opened, branch roads are recovered, branch roads are renovated, entrances and exits are adjusted, motor vehicles are prohibited from turning left or right at intersections, and motor vehicles are organized to travel in one direction; Construct one-way traffic network: according to the traffic flow characteristics of different road networks, form fixed one-way traffic, time-line one-way traffic, reversible one-way traffic, and one-way traffic with characteristics of vehicle types; Construct a left turn-free traffic network: Priority should be given to implementing left turn-free restrictions on roads affected by frequent traffic congestion and the regional road network composed of their connected roads to ensure the accessibility of traffic to and from the destination; Build a public transportation network: Build a public transportation network on urban expressways and trunk roads; Construct an orderly and smooth road section based on the parameter values ​​of each indicator layer of the traffic section layer: When the road cross-section scale and traffic flow matching degree M<0.6, or M>0.9, the number of lane scales of the road section is adjusted and optimized; When the motor vehicle traffic organization efficiency EM is less than 0.6, the public transportation organization efficiency ET is less than 0.6, and the slow traffic organization efficiency EP is less than 0.6, the lane width, road section entrance and exit, road cross section, central median opening, bus stop location and form, pedestrian crossing location and form, and main and auxiliary entrance and exit locations and forms are optimized; When the traffic flow imbalance coefficient P>0.2, a tidal lane is set for the road section; According to the parameter values ​​of each indicator layer of the traffic node layer, safe and efficient nodes are constructed: When the number of matching lanes of the left-turn upstream and downstream lanes at the node SL is less than 0, the number of matching lanes of the straight-through upstream and downstream lanes at the node SS is less than 0, or the number of matching lanes of the right-turn upstream and downstream lanes at the node SR is less than 0, the number of entrance and exit lanes of the node intersection is adjusted, increasing the number of lanes of the upstream entrance lane of the node intersection or reducing the number of lanes of the downstream exit lane of the node intersection, so that the values ​​of SL, SS, and SR are ≥ 0 respectively; When the road grade in the road network with frequent traffic congestion is a city trunk road, and the distance between two intersection nodes R is less than 600m; when the grade is a city secondary road, and the distance between two intersection nodes is less than 300m, the intersection nodes are controlled and adjusted to: left and right entry and exit are prohibited at grade-separated intersections and traffic light-controlled intersections; When the smoothness of node traffic flow organization N is less than 0.7, optimize and adjust the node intersection entrance channelization, exit channelization, and intersection channelization; Among them, the entrance channelization includes the optimization of the number of lanes, lane width, functional division, stop line position, gradient section length, widening section length, left-turn lane, right-turn lane, and U-turn lane; Exit channelization includes optimization of lane number, lane width, functional division, gradient section length, and widening section length; Channelization within intersections includes optimization of diversion lines and diversion islands; When the node traffic signal control efficiency EC is less than 0.7, optimize and adjust the traffic control mode, traffic signal phase, and traffic signal timing.

7. The method for alleviating frequent traffic congestion on urban roads according to claim 1, characterized in that: In step 5), a simulation model is established based on the road network relief plan for frequent traffic congestion, and the steps for verifying the effectiveness of the relief plan are as follows: First, a preliminary simulation model was constructed using the simulation software VISSIM; Secondly, based on the established preliminary model, according to the traffic characteristics of the road network relief plan for frequent traffic congestion, simulation models of various relief plans for balanced regional road networks, various relief plans for orderly and unobstructed sections, and various relief plans for efficient operation nodes are established: Finally, set the evaluation type, run the simulation and output the results to verify the effectiveness of the solution.

8. The method for alleviating frequent traffic congestion on urban roads according to claim 7, characterized in that: The construction of a preliminary simulation model using the simulation software VISSIM mainly includes: drawing a CAD road network with frequent traffic congestion as the base map of the simulation model; defining traffic attributes, setting input driving behavior parameters, expected speed distribution, and parking time distribution; defining road network attributes, inputting current traffic flow and current traffic control methods based on actual traffic flow data, adding road sections and connectors, and defining vehicle input and path decisions; The steps to establish the simulation model of each relief scheme for the balanced regional road network are: ① Improve the road network framework; ② Divert transit traffic, establish a freight transportation network, and implement regional traffic restrictions; ③Build a micro-circulation traffic network, a one-way traffic network, a left-no-turn traffic network, and a public transportation network; The steps to establish the simulation model of each relief plan for orderly and unobstructed road sections are: ① Increase or decrease the number of lanes; ② Optimization of lane width, road section entrances and exits, road cross-section, central median opening, bus stop location and form, pedestrian crossing location and form, main and auxiliary entrances and exits location and form; ③ Setting up tidal lanes on the road sections; (3) The steps to establish the simulation model of each decongestion solution for efficient operation nodes are as follows: ① Adjustment of the number of matching lanes at the upstream and downstream nodes; ② Stereoscopic intersection optimization; ③ Channelization of node intersection entrances, exits and intersections; ④ Adjust traffic control methods, traffic signal phases, and traffic signal timing; At the road network level, the evaluation type indicator is set as travel time; at the road section level, the evaluation type indicator is set as operating speed; at the node level, the evaluation type indicator is set as delay time and queue length.

9. An electronic device, characterized in that: The equipment includes: a memory for storing executable computer programs; The processor is used to implement the method for alleviating common traffic congestion on urban roads as described in any one of claims 1 to 8 when executing the executable computer program stored in the memory.

10. A computer-readable storage medium, characterized in that: A computer program is stored, which is used to implement the method for alleviating common traffic congestion on urban roads as described in any one of claims 1 to 8 when executed by a processor.

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