A step-by-step transition adjustment method for traffic organization during road closure construction

Abstract

The invention discloses a method for step-by-step transition adjustment of traffic organization for road full closure construction, which relates to the technical field of traffic management and control, including obtaining checkpoint passing data, intersection signal control scheme data and intersection channelization data of the surrounding intersections of the construction section for nearly one month, and gradually reducing the traffic flow leading to the construction section from all directions of the upstream and downstream intersections of the construction section by adjusting the traffic signal timing and the direction of the import lane before the road is fully closed for construction, so as to achieve the purpose of gradually reducing the traffic flow of the construction section, and then gradually adjusting the traffic organization of the surrounding intersections where the traffic flow of the construction road is gradually reduced. In this way, on the one hand, the gradual flow reduction leaves a gradual adaptation process for the driver, and on the other hand, it can effectively ensure the feasibility of the traffic organization scheme of the surrounding intersections, thereby avoiding the occurrence of large-scale traffic congestion or traffic paralysis.

Description

Technical Field

[0001] The invention relates to the technical field of traffic management and control, and in particular to a traffic organization step-by-step transition adjustment method for road full closure construction. Background Art

[0002] With the acceleration of my country's urbanization process, the number of road infrastructure construction projects is increasing, the impact of road construction is increasing, and the road construction period is long, causing problems such as traffic congestion at intersections around the construction section. How to effectively organize and manage traffic during road construction and effectively coordinate the relationship between traffic diversion and construction has gradually become a key issue in urban road construction. At present, the traffic organization method for intersections around construction sections is to adopt a set of fixed traffic diversion and relief plans based on the design experience of traffic engineers and the management experience of traffic police. This method does not conduct quantitative analysis based on the traffic demand of intersections around construction roads, and has great limitations, making it difficult to effectively divert traffic at intersections around construction sections.

[0003] In the existing improved technical methods, such as patent CN112950940B, the traffic impact area of ​​the construction section is first determined based on the service level of the intersections around the construction section, and then the vehicles are diverted according to the service level load of the internal roads in the traffic impact area to obtain different traffic diversion schemes, and then the traffic diversion schemes are simulated and evaluated using VISSIM software to select a set of optimal traffic diversion schemes. Although this method has obtained the traffic organization plan for the intersections around the construction section on the premise of analyzing the traffic demand of the intersections around the construction road, for the fully closed construction road, due to the sharp increase in traffic diversion pressure, if the plan is directly implemented in this case, on the one hand, it may be difficult for drivers to adapt to the plan in a short time and easily lead to traffic chaos, and on the other hand, it may cause traffic congestion due to the plan not fully meeting the release conditions of the road network traffic or the changes in traffic flow at different times, which will have an adverse impact on the traffic congestion around the construction road, and it is very likely to cause large-scale traffic paralysis in a short period of time after the plan is implemented.

[0004] Therefore, it is urgent to study a reasonable method for adjusting the traffic organization around the construction road, improve the applicability of traffic diversion at surrounding intersections after the road is fully closed for construction, and effectively avoid the occurrence of large-scale traffic congestion.

[0005] On the one hand, a gradual adaptation process is given to drivers, and on the other hand, the implemented plans are tracked, evaluated and adjusted in a timely manner, ultimately determining a set of implementation plans for traffic organization at intersections around the construction section under the conditions of full road closure construction that is adaptable to drivers, meets the road network traffic release conditions and the changing traffic flow requirements at different times, so as to improve the applicability of traffic diversion at surrounding intersections after full road closure construction and effectively avoid the occurrence of large-scale traffic congestion. Summary of the invention

[0006] In order to make up for the shortcomings of the existing technical problems, the purpose of the present invention is to provide a step-by-step transition adjustment method for traffic organization for full road closure construction. According to the checkpoint passing data, signal phase timing data and intersection channelization data of the surrounding intersections of the construction section in the past month, the traffic flow leading to the construction section from all directions of the upstream and downstream intersections of the construction section is gradually reduced by adjusting the traffic signal timing and the direction of the import lane, so as to achieve the purpose of gradually reducing the traffic flow of the construction section, and then the traffic organization of the surrounding intersections where the traffic flow of the construction road is gradually reduced is adjusted step by step. On the one hand, the gradual flow reduction leaves a gradual adaptation process for the driver, and on the other hand, it can effectively ensure the feasibility of the traffic organization plan of the surrounding intersections, thereby avoiding the occurrence of large-scale traffic congestion or traffic paralysis.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A traffic organization step-by-step transition adjustment method for road full closure construction includes the following steps:

[0009] (1) Obtain the traffic data, signal control scheme data, and channelization data of the checkpoints around the construction section for the past month, and clean, match, and calculate the above data to obtain the one-hour traffic flow design data for different entrance directions and time periods at the intersections around the construction section on an average day;

[0010] (2) Before the road is fully closed for construction, the traffic flow from all directions at the upstream and downstream intersections of the construction section will be gradually reduced by adjusting the traffic signal timing and the direction of the entrance lanes, so as to achieve the purpose of gradually reducing the traffic flow on the construction section:

[0011] 2.1) Determine the first reduction ratio of traffic flow in the construction section, reduce the traffic flow design data of each flow direction entering the construction section at different inlet and downstream intersections of the construction section according to the set ratio, redistribute the reduced traffic flow in the flow direction leading to the construction section to other flow directions, and obtain the adjusted traffic flow design data of each flow direction;

[0012] 2.2) Calculate the adjusted total periodic flow rate ratio Y of the intersection, and determine whether the adjusted total periodic flow rate of the intersection is less than a threshold;

[0013] ① If the adjusted total cycle flow rate of the intersection is less than the threshold, proceed to the next step;

[0014] ② If the total cycle flow rate of the adjusted intersection is greater than the threshold, the import lane allocation plan is optimized to reduce the traffic flow rate ratio of the corresponding flow direction without changing the existing phase plan; if the optimized import lane allocation plan cannot make the total cycle flow rate of the adjusted intersection less than the threshold, it is necessary to find the upstream intersection corresponding to the flow direction with the largest traffic flow rate ratio of the intersection to limit the flow until the total cycle flow rate of the adjusted intersection is less than the threshold; the upstream intersection also needs to re-optimize the lane or limit the flow of its upstream intersection according to this method until the total cycle flow rate of the upstream intersection after the adjustment is calculated to be less than the threshold;

[0015] 2.3) Calculate the saturation of each flow direction and determine whether each flow direction is in a saturated state

[0016] ① If all traffic directions are not in a saturated state, a preliminary traffic flow diversion plan for the intersections around the construction section is obtained;

[0017] ② If one of the import flows is in an oversaturated state, first do not change the existing phase plan, and adjust the import lane allocation plan and signal timing to reduce the saturation of the corresponding flow direction; if adjusting the import lane allocation plan and signal timing cannot make the import flow meet the conditions, it is necessary to find the upstream intersection corresponding to the flow direction to limit the flow, and the upstream intersection also needs to re-optimize the timing, lanes or limit the flow of the upstream intersection according to the above method until the saturation of each import flow direction at the upstream intersection is calculated to be less than the threshold; and a preliminary traffic flow guidance and relief plan for the intersections around the construction section is obtained;

[0018] 2.4) After the preliminary traffic flow diversion plan at the intersections around the construction section has been implemented for a period of time, the traffic flow on the construction section will be reduced step by step according to the above steps until the traffic flow on the construction section is reduced by 100%, and then the construction section will be completely closed.

[0019] The checkpoint vehicle passing data includes the vehicle passing ID, intersection number, entrance road direction, flow direction, lane number, license plate number, vehicle type, and vehicle passing time;

[0020] The intersection signal control scheme data includes intersection time period division data, phase scheme design data and intersection signal timing data.

[0021] The steps for obtaining the one-hour traffic flow design data of different inlet flow directions at the intersections around the construction section in step (1) are as follows:

[0022] ① Obtain the daily vehicle passing data of each entrance direction and time period at the intersections around the construction section within one month;

[0023] ② Collect statistics on the maximum 15-minute traffic flow data of each entrance flow direction and time period at the intersections around the construction section every day within one month, and add and average the maximum 15-minute traffic flow data of each entrance flow direction and time period in one day:

[0024] in, It represents the sum of the maximum 15-minute traffic flow data of one import flow direction in one period within a month;

[0025] ③ Determine the design data of the average one-hour traffic flow at different entrance directions and time periods at the intersections around the construction section:

[0026] The steps to redistribute the reduced traffic flow in the direction leading to the construction section to other directions are as follows:

[0027] Turn left at the north entrance: q′ nl =(1-α)q nl ;

[0028] Go straight from the north entrance:

[0029] Turn right at the north entrance:

[0030] Turn left at the south entrance:

[0031] South entrance straight ahead:

[0032] Turn right at the south entrance: q s ' r =(1-α)q sr ;

[0033] Turn left at the west entrance:

[0034] Go straight from the west entrance: q′ wt =(1-α)q wt ;

[0035] Turn right at the west entrance:

[0036] Turn left at the east entrance: q′ el =(1-α)q el ;

[0037] East entrance straight: q′ es =(1-α)q es ;

[0038] Turn right at the east entrance: q′ er =(1-α)q er ;

[0039] Among them, q nl ,q nt ,q nrare the design traffic flow data for the left, straight and right directions of the north entrance of the intersection, respectively. sl ,q st ,q s are the design flow data for the left, straight and right directions of the south entrance, respectively, wl ,q wt ,q wr are the design flow data for the left, straight and right directions of the west entrance, respectively, el ,q et ,q er are the design data of traffic flow in the left, straight and right directions of the east entrance respectively; α is the reduction ratio of traffic flow in the construction section; q′ nl ,q′ nt ,q′ nr They are the design flow data of the north entrance after adjustment for the left, straight and right flow directions; q s ' l ,q s ' t ,q s ' r are the design flow data of the south entrance after adjustment for the left, straight and right flow directions; q′ wl ,q′ wt ,q′ wr are the design flow data of the west entrance after adjustment for the left, straight and right directions; q′ el ,q′ et ,q e ' r These are the design traffic flow data after adjustments for the left, straight and right flow directions at the east entrance.

[0040] The steps for calculating the adjusted total cycle flow rate ratio Y of the intersection are as follows:

[0041] (2) Determine the traffic flow rate ratio:

[0042]

[0043] In the formula, y i represents the traffic flow rate ratio of each entrance flow direction at the intersection, q i Indicates the traffic flow design data of each entrance flow direction of the intersection, N i Indicates the number of lanes for each entrance flow at the intersection, S i Indicates the saturated flow rate of each inlet flow direction of the intersection;

[0044] Substituting the traffic flow design data after adjustment of each entrance flow direction at the intersection, the number of lanes and the saturation flow rate of each entrance flow direction into formula (1), the traffic flow rate ratio of each entrance flow direction at the intersection is obtained:

[0045]

[0046] q′ nl ,q′ nt They are the design flow data of the north entrance left and straight flow directions after adjustment; q s ' l ,q s ' t are the design flow data of the left and straight flow directions of the south entrance after adjustment; q′ wl ,q′ wt are the design flow data of the left and straight flow directions after adjustment at the west entrance; q′ el ,q′ et are the adjusted traffic flow design data for the left and straight directions of the east entrance; the number of lanes for the left and straight directions of the north entrance of the intersection is N nl 、N n ; The number of lanes for left and straight flow at the south entrance is N sl 、N st ; The number of lanes for left and straight flow at the west entrance is N wl 、N wt ; The number of lanes for left and straight flow at the east entrance is N el 、N et ;

[0047] Calculate the cycle flow rate ratio:

[0048] Y=∑y i =max(y1,y2)+max(y3,y4)+max(y5,y6)+max(y7,y8) (2)

[0049] Where Y represents the total cycle flow rate ratio of an intersection.

[0050] The specific steps for calculating the saturation of each flow direction are as follows:

[0051] (1) Calculate the total loss time

[0052] For the sake of simplicity, the yellow light time A is 3 seconds, the full red time r is 0 seconds, the green light interval time I is 3 seconds, and the start loss time l is 3 seconds;

[0053] The total loss time L of the cycle is calculated using the formula:

[0054]

[0055] (2) Determine the cycle length C:

[0056]

[0057] (3) Calculate the total effective green light time G E :

[0058] G E =∑g ei =CL (5)

[0059] (4) Calculate the effective green light time g for each phase ei :

[0060]

[0061] (5) Calculate the minimum green light time g min :

[0062]

[0063] In the formula, g min is the shortest green light time, dimension is s; L P is the length of the street for pedestrians to cross, with the dimension of m; V P is the walking speed of pedestrians crossing the street, V P It is defined as 1.2m / s; I is the green light interval time, the dimension is s;

[0064] In order to make the signal timing scheme meet the traffic needs of vehicles and pedestrians at the intersection, the effective green light time g of each phase is ei Must be greater than or equal to the minimum green light time g of each phase mini The solution is g ei Multiply by the adjustment factor f, when g ei ≥g mini When f is 1, when g ei <g mini When f is equal to g mini With g ei The maximum ratio, that is, max(g jmin / g ej ), get the adjusted effective green light duration Further determine the adjusted cycle length C′;

[0065] (6) Calculate the green light time g for each phase i :

[0066]

[0067] (7) Calculate the saturation x of each flow direction i ;

[0068]

[0069] In the formula, λ i is the green-to-signal ratio of each flow direction.

[0070] After a preliminary traffic flow guidance and relief plan for the intersections around the construction section is obtained, it is implemented at the intersections around the construction section for one day. The saturation of the flow directions of each inlet of the surrounding intersections that need to be diverted is calculated in different time periods based on the data of the day. If the saturation is less than the threshold, it meets the requirements. The plan is implemented the next day. If the saturation does not meet the requirements, the traffic flow guidance and relief plan for the intersections around the construction section is updated and adjusted according to the above method based on the data of the day. This process is repeated until the plan is applicable for a period of time. Then a set of traffic flow guidance and relief plans for the surrounding intersections that meet the traffic flow diversion of the construction section can be determined, so that the traffic flow at the intersections around the construction section is balanced.

[0071] Compared with the prior art, the present invention has the following beneficial effects:

[0072] On the one hand, a gradual adaptation process is given to drivers, and on the other hand, the implemented plans are tracked, evaluated and adjusted in a timely manner, ultimately determining a set of implementation plans for traffic organization at intersections around the construction section under the conditions of full road closure construction that is adaptable to drivers, meets the road network traffic release conditions and the changing traffic flow requirements at different times, so as to improve the applicability of traffic diversion at surrounding intersections after full road closure construction and effectively avoid the occurrence of large-scale traffic congestion.

[0073] 1. In the present invention, before the road is fully closed for construction, the traffic flow from the upstream and downstream intersections of the construction section to the construction section in all directions is gradually reduced by adjusting the traffic signal timing and the direction of the import lane, so as to achieve the purpose of gradually reducing the traffic flow of the construction section, and then a method for step-by-step adjustment of the traffic organization of the surrounding intersections with the gradually reduced traffic flow of the construction road is established, and finally a set of traffic flow guidance and relief plans for the construction section surrounding intersections that meet the 100% traffic flow diversion of the construction section is determined. In this process, on the one hand, the gradual flow reduction leaves a gradual adaptation process for the driver, and on the other hand, the total cycle flow rate ratio of the intersection and the saturation of each flow direction are used as judgment criteria, and the traffic organization of the surrounding intersections is adjusted step by step by adjusting the import lane allocation plan, signal timing and reducing the traffic flow of the upstream intersection into the intersection, which can effectively ensure the feasibility of the traffic organization plan of the surrounding intersections, thereby avoiding the occurrence of large-scale traffic congestion or traffic paralysis.

[0074] 2. The present invention tracks, evaluates and adjusts the preliminary traffic flow guidance and relief plan for the intersections around the construction section for a period of time, and finally determines a set of traffic organization implementation plans for the intersections around the construction section under the conditions of full road closure construction that are adaptable to drivers, meet the road network traffic release conditions and the traffic flow changes at different time periods, so as to improve the applicability of traffic diversion at the surrounding intersections after the road is fully closed for construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 The present invention is a flow chart of the method.

[0076] Figure 2 This is the data structure of the vehicle passing through the checkpoint of the present invention.

[0077] Figure 3 It is a schematic diagram of the intersections around the construction section of the present invention.

[0078] Figure 4 This is a flow chart for verifying the timing scheme of the present invention.

[0079] Figure 5 It is a schematic diagram of a temporary movable variable directional lane indicator screen of the present invention.

[0080] Figure 6 This is a schematic diagram of the intersection required for diversion after the traffic volume of the construction section is gradually reduced according to the present invention.

[0081] Figure 7 This is the phase diagram corresponding to intersection 1 after the traffic volume in the construction section of the present invention is reduced by 100%.

[0082] Figure 8 It is a schematic diagram of the implementation scheme of the traffic organization engineering at the intersections around the construction section of the present invention. DETAILED DESCRIPTION

[0083] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0084] like Figure 1-8 As shown, a traffic organization step-by-step transition adjustment method for road full closure construction includes the following steps:

[0085] 1. Build an information data resource library for intersections around fully enclosed construction roads

[0086] Obtain the vehicle passing data, intersection signal control plan data and intersection channelization data at the intersections around the construction section for the past month.

[0087] (1) Constructing the data of vehicle passing through the checkpoint: The checkpoint equipment is generally arranged near the stop line of the entrance road in each direction of the intersection, 10 to 30 meters away from the stop line. On the one hand, it monitors and photographs vehicles that violate the law at the intersection, and on the other hand, it records every vehicle passing through the intersection in real time. The structure of the vehicle passing data obtained by the checkpoint equipment is as follows: Figure 2 As shown, it mainly includes the vehicle passing ID, intersection number, entrance road direction, flow direction, lane number, license plate number, vehicle type, and passing time.

[0088] (2) Obtaining signal control plan data: The intersection signal control plan data is mainly obtained by the signal control platform, including intersection time division data, phase plan design data and intersection signal timing data.

[0089] (3) Construct intersection channelization data: Intersection channelization data is obtained through electronic maps, manual on-site surveys, etc.

[0090] (4) By cleaning, matching and calculating the above data:

[0091] ① Obtain the daily vehicle passing data of each entrance direction and time period at the intersections around the construction section within one month;

[0092] ② Collect statistics on the maximum 15-minute traffic flow data of each entrance flow direction and time period at the intersections around the construction section every day within one month, and add and average the maximum 15-minute traffic flow data of each entrance flow direction and time period in one day:

[0093] in, It represents the sum of the maximum 15-minute traffic flow data of one import flow to one time period within a month.

[0094] ③ Determine the design data of the average one-hour traffic flow at different entrance directions and time periods at the intersections around the construction section:

[0095] 2. Establish a method for adjusting traffic organization at surrounding intersections step by step with a gradual decrease in traffic volume on construction roads

[0096] Before the road is fully closed for construction, the traffic flow from the upstream and downstream intersections of the construction section in all directions is gradually reduced by adjusting the traffic signal timing and the direction of the entrance lane, so as to achieve the purpose of gradually reducing the traffic flow of the construction section. The process of gradually reducing the traffic flow of the construction section should take into account that drivers can gradually adapt and should not affect the construction progress. Therefore, the gradual reduction of the traffic flow of the construction section should not be too large or too small, and can be set to gradually reduce the traffic flow of the construction section by 20%.

[0097] like Figure 3 Assuming that intersections 1 and 2 are the upstream and downstream intersections of the construction section, respectively, taking intersection 1 as an example, the design traffic flow data for the left, straight, and right directions of the north entrance of intersection 1 is q nl ,q nt ,q nr , the number of lanes is N nl 、N nt 、N nr ; The design data of traffic flow in the left, straight and right directions of the south entrance is q sl ,q st ,q sr, the number of lanes is N sl 、N st 、N sr ; The design data of the traffic flow in the left, straight and right directions of the west entrance is q wl ,q wt ,q wr , the number of lanes is N wl 、N wt 、N wr ; The design data of traffic flow in the left, straight and right directions of the east entrance is q el ,q et ,q er , the number of lanes is N el 、N et 、N er The traffic directions from intersection 1 to the construction section are north left turn, east straight and south right turn, and the corresponding traffic flow design data are q nl ,q et and q sr Therefore, the design data of traffic flow from intersection 1 to the construction section during this period is:

[0098] Q=q nl +q et +q sr

[0099] First, reduce the traffic volume of the construction section by 20%, which is equivalent to reducing the traffic volume design data of the construction section by 20%. Correspondingly, the traffic volume design data of each flow direction entering the construction section from different entrances of the upstream and downstream intersections of the construction section must be reduced by 20%. For example, the traffic volume design data of the north left turn, east straight and south right turn entering the construction section of intersection 1 are reduced by 20% respectively. The traffic volume design data of different entrances of intersection 2 entering the construction section also need to be reduced by 20%. Since the east entrance of intersection 1 is the output direction of the traffic volume entering the construction section of intersection 2, the traffic volume design data of each flow direction at the east entrance of intersection 1 need to be reduced by 20%. In order to balance the traffic volume of each entrance flow direction of intersection 1, the reduced traffic volume of the flow direction leading to the construction section needs to be redistributed to other flow directions. Suppose the traffic volume design data of each entrance flow direction of intersection 1 are adjusted as follows: the north entrance left, straight and right are q′ respectively nl ,q′ nt ,q′ nr ; The left, straight and right entrances to the south are q s ' l ,q s ' t ,q s ' r ; The left, straight and right entrances to the east are q e ' l ,q e 't ,q e ' r ; The left, straight and right entrances to the west are q′ respectively wl ,q′ wt ,q′ wr The relationship between the design data of traffic flow in each direction before and after adjustment is shown in Table 1.

[0100] Table 1 Relationship table of design data of traffic flow in each direction before and after adjustment

[0101]

[0102] After the design data of traffic flow at each inlet is determined, the current four-phase scheme is taken as an example to re-optimize the timing scheme and execute the timing scheme verification process, such as Figure 4 The timing scheme verification process is as follows:

[0103] (1) Determine the traffic flow rate ratio:

[0104]

[0105] In the formula, y i represents the traffic flow rate ratio of each entrance flow direction at the intersection, q i Indicates the traffic flow design data of each entrance flow direction of the intersection, N i Indicates the number of lanes for each entrance flow at the intersection, S i Indicates the saturated flow rate of each inlet flow direction of the intersection.

[0106] Substitute the adjusted traffic flow design data of each entrance flow direction of intersection 1, the number of lanes of each entrance flow direction and the saturated flow rate into formula 1 to obtain the traffic flow rate ratio of each entrance flow direction of intersection 1:

[0107]

[0108] Calculate the cycle flow rate ratio:

[0109] Y=∑y i =max(y1,y2)+max(y3,y4)+max(y5,y6)+max(y7,y8) (2)

[0110] Where Y represents the total cycle flow rate ratio of an intersection.

[0111] (2) Determine the size of Y and 0.9

[0112] ①If Y<0.9, proceed to the next step of calculation;

[0113] ② If Y ≥ 0.9, that is, the Y value does not meet the requirements, find the flow direction corresponding to the maximum traffic flow rate ratio and take measures to reduce the traffic flow rate ratio of this flow direction.

[0114] In order not to change the original traffic habits of drivers, the existing phase plan is generally not changed. The import lane allocation plan can be optimized to reduce the corresponding flow rate ratio y, thereby reducing the Y value. The optimized import lane allocation plan must meet the requirement that there must be at least one lane in each flow direction. When all import lane combination plans are traversed and Y≥0.9 is calculated by formula (1) and formula (2), it is necessary to find the upstream intersection corresponding to the flow direction corresponding to the maximum value of the traffic rate ratio of the intersection (such as the upstream intersection 8 corresponding to intersection 1) for flow restriction. In order to ensure the continuity of traffic flow changes, the traffic flow of the upstream intersection into the intersection can be reduced by 10% each time. After each reduction, the traffic flow design data of the corresponding import flow direction of the intersection is reduced by 10% accordingly. The adjusted traffic flow design data is recalculated according to formula (1) and formula (2) until Y<0.9 of the intersection is calculated. Each time the traffic volume flowing into the import from the upstream intersection is reduced by 10%, the upstream intersection also needs to re-optimize the lanes or limit the flow at its upstream intersection (such as upstream intersection 9 corresponding to intersection 8) according to the above method, until the Y of the upstream intersection is calculated to be less than 0.9, and so on, until the Y values ​​of the surrounding intersections that need to be diverted after the traffic volume of the construction section is reduced by 20% are all less than 0.9, then the next step of calculation can be carried out.

[0115] (3) Calculate the total loss time

[0116] For the sake of simplicity in calculation, the phase yellow light time A is 3 seconds, the full red time r is 0 seconds, then the green light interval time I is 3 seconds, and the starting loss time l is 3 seconds.

[0117] The total lost time of the cycle is calculated using the formula:

[0118]

[0119] (4) Determine the cycle duration:

[0120]

[0121] (5) Calculate the total effective green light time G E :

[0122] G E =∑g ei =CL (5)

[0123] (6) Calculate the effective green light time of each phase:

[0124]

[0125] (7) Calculate the minimum green light time g min :

[0126]

[0127] In the formula, g min is the shortest green time, s;

[0128] L P is the length of the street for pedestrians to cross, m;

[0129] V P The walking speed of pedestrians crossing the street is 1.2m / s;

[0130] I is the green light interval time, s.

[0131] In order to make the signal timing scheme meet the traffic needs of vehicles and pedestrians at the intersection, the effective green light time g of each phase is ei Must be greater than or equal to the minimum green light time g of each phase mini The solution is g ei Multiply by the adjustment factor f (when g ei ≥g mini When f is 1, when g ei <g mini When f is equal to g mini With g ei The maximum ratio, that is, max(g jmin / g ej )) to get the adjusted effective green light duration The adjusted cycle duration C′ is further determined.

[0132] (8) Calculate the green light time for each phase:

[0133]

[0134] (9) Calculate the saturation x of each flow direction i ;

[0135]

[0136] In the formula, λ i is the green-to-signal ratio of each flow direction.

[0137] If it is calculated that one of the import flows of the intersection is in an oversaturated state, that is, the saturation is greater than 0.95, then the import flow of the intersection will be congested and paralyzed. In order not to change the original traffic habits of drivers, the existing phase plan is generally not changed. The import lane allocation plan and signal timing are adjusted to reduce the saturation of the corresponding flow direction. The optimized import lane allocation plan must meet the requirement that there must be at least one lane for each flow direction. When all the import lane combination plans are traversed and the saturation of the flow direction is calculated by equations (1) to (9) to be greater than 0.95, it is necessary to find the upstream intersection corresponding to the flow direction (such as the upstream intersection 8 corresponding to intersection 1) for flow restriction. In order to ensure the continuity of traffic flow changes, the traffic flow of the upstream intersection into the intersection can be reduced by 10% each time. After each reduction, the traffic flow design data of the corresponding import flow direction of the intersection is reduced by 10% accordingly. The adjusted traffic flow design data is calculated according to equations (1) to (9) to calculate the saturation until the saturation of the flow direction is calculated to be less than 0.95. Each time the traffic volume flowing into the import from the upstream intersection is reduced by 10%, the upstream intersection also needs to re-optimize the timing, lanes or limit the flow of the upstream intersection (such as the upstream intersection 9 corresponding to intersection 8) according to the above method, until the saturation of each import flow direction of the upstream intersection is calculated to be less than 0.95, and so on, until the saturation of each import flow direction of the surrounding intersections that need to be diverted after the traffic volume of the construction section is reduced by 20% is less than 0.95, stop the iterative calculation, and obtain a preliminary traffic flow guidance and relief plan for the intersections surrounding the construction section.

[0138] After a preliminary traffic flow guidance and relief plan for the intersections surrounding the construction section is obtained, it is implemented for one day at the intersections surrounding the construction section. The saturation of the flow directions of each inlet at the surrounding intersections that need to be diverted is calculated in different time periods based on the data of the day. If the saturation is less than 0.95, it meets the requirements. The plan is implemented the next day. If the saturation does not meet the requirements, the traffic flow guidance and relief plan for the intersections surrounding the construction section is updated and adjusted according to the above method based on the data of the day. This process is repeated until the plan is applicable for one week. A set of traffic flow guidance and relief plans for the intersections surrounding the construction section that can divert 20% of the traffic flow of the construction section can be determined, so that the traffic flow at the intersections surrounding the construction section is balanced, and temporary mobile variable directional lane indicator screens are placed at the upstream sections of all intersections that need to be diverted to guide vehicle diversion in a timely manner. Figure 5As shown in the figure, the temporary mobile variable lane indicator screen is divided into two parts: an LED variable lane indicator device and a traffic guidance screen. The LED variable lane indicator device retains a left turn and a right turn lane. The middle lane is equipped with an embedded LED display device, which supports switching between three states: straight, left turn, and right turn, so as to realize the conversion of the lane traffic direction at the intersection. The traffic guidance screen displays "Road construction ahead, please follow the lane instructions". A solar power supply panel is installed on the top of the temporary mobile variable lane indicator screen to power the temporary mobile variable lane indicator screen with solar energy; the bottom is a rectangular structure, and a universal wheel is installed at each of the four corners of the bottom surface, in order to ensure that the temporary mobile variable lane indicator screen can be easily moved and can be stabilized when in use. The temporary mobile variable lane indicator screen is placed in front of the original lane sign of the upstream section of the intersection where diversion is required, and the original lane sign is covered with a blue film, and the guide arrow marking corresponding to the import lane that needs to change direction is erased.

[0139] By analogy, the traffic volume of the construction section is gradually reduced by 40%, 60%, 80%, and 100%. Each time the traffic volume of the construction section is reduced, the number of intersections that need to be diverted and relieved will increase. Figure 6 The intersections included in the purple line represent the intersections that need to be diverted after the construction section reduces the traffic volume by 20%; the intersections included in the purple and green line segments represent the intersections that need to be diverted after the construction section reduces the traffic volume by 40%; the intersections included in the purple, green, and blue line segments represent the intersections that need to be diverted after the construction section reduces the traffic volume by 60%; the intersections included in the purple, green, blue, and yellow line segments represent the intersections that need to be diverted after the construction section reduces the traffic volume by 80%; the intersections included in the purple, green, blue, yellow, and red line segments represent the intersections that need to be diverted after the construction section reduces the traffic volume by 100%. According to the above method, the traffic flow guidance and relief plans for the surrounding intersections corresponding to the step-by-step reduction of the traffic volume on the construction section were determined, and finally a set of traffic flow guidance and relief plans for the surrounding intersections that meet the 100% traffic flow diversion of the construction section were determined. When the traffic volume of the construction section is reduced by 100%, the traffic volume and number of lanes at each entrance to the construction section at the upstream and downstream intersections of the construction section are 0. At this time, the upstream and downstream intersections of the construction section are all T-shaped intersections, and their phase scheme can be set according to the signal phase scheme of the T-shaped intersection. Figure 3 As shown, taking the upstream intersection 1 of the construction section as an example, when the traffic volume of the construction section is reduced by 100%, the construction section is completely closed, and the east entrance of the corresponding intersection 1 is closed. The phase diagram is as follows Figure 7 As shown, there are three phases, namely, west left turn, north-south straight driving and south left turn, among which the passable right turn flow direction does not need to be controlled.

[0140] 3. Determine the implementation plan for traffic organization engineering at intersections around the construction section under the condition of full road closure

[0141] Based on a set of traffic flow guidance and relief plans for the surrounding intersections that can divert 100% of the traffic flow on the construction section, determine the implementation plan for the traffic organization project at the surrounding intersections of the fully closed road construction. At the intersections around the construction section where traffic organization is required, adjust the corresponding import lane guide arrow markings, directional lane signage to indicate the direction and signal timing, and further install signs prohibiting driving in a certain direction at the entrances of the upstream and downstream intersections of the construction section, and attach and install auxiliary signs for construction section diversion information on the poles of the original directional lane signs at the entrances of the upstream and downstream intersections of the construction section. Figure 8 As shown, in addition to optimizing signal timing, it is necessary to adjust the corresponding import lane guide arrow markings and directional lane sign directions at intersections 3, 4, 5, 6, 7, and 8 around the construction section, and adjust the corresponding import lane guide arrow markings and directional lane sign directions at intersections 1 and 2 upstream and downstream of the construction section, and install signs prohibiting driving in a certain direction and auxiliary signs for diversion information of the construction section. Taking the south entrance of intersection 1 upstream of the construction section as an example, the import lane markings and directional lane sign directions of the south entrance direction are uniformly adjusted to two straights and one left turn, and the auxiliary sign for diversion information of the section displays "The right turn ahead is a construction section, please take a detour". After the above project implementation plan is completed, the construction road can be fully closed for construction.

[0142] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for step-by-step transition adjustment of traffic organization for road full closure construction, characterized in that: The following steps are involved: (1) Obtain the traffic data, signal control scheme data, and channelization data of the checkpoints around the construction section for the past month, and clean, match, and calculate the above data to obtain the one-hour traffic flow design data for different entrance directions and time periods at the intersections around the construction section on an average day; (2) Before the road is fully closed for construction, the traffic flow from all directions at the upstream and downstream intersections of the construction section shall be gradually reduced by adjusting the traffic signal timing and the direction of the entrance lanes, so as to achieve the purpose of gradually reducing the traffic flow of the construction section, as follows: 2.1) Determine the traffic flow reduction ratio of the construction section, reduce the traffic flow design data of each flow direction entering the construction section at different inlet and downstream intersections of the construction section according to the set ratio, redistribute the reduced traffic flow of the flow direction leading to the construction section to other flow directions, and obtain the adjusted traffic flow design data of each flow direction; 2.2) Calculate the adjusted total periodic flow rate ratio Y of the intersection, and determine whether the adjusted total periodic flow rate of the intersection is less than a threshold; ① If the adjusted total cycle flow rate of the intersection is less than the threshold, proceed to the next step; ② If the total cycle flow rate of the adjusted intersection is greater than the threshold, the import lane allocation plan is optimized to reduce the traffic flow rate ratio of the corresponding flow direction without changing the existing phase plan; if the optimized import lane allocation plan cannot make the total cycle flow rate of the adjusted intersection less than the threshold, it is necessary to find the upstream intersection corresponding to the flow direction with the largest traffic flow rate ratio of the intersection to limit the flow until the total cycle flow rate of the adjusted intersection is less than the threshold; the upstream intersection also needs to re-optimize the lane or limit the flow of its upstream intersection according to this method until the total cycle flow rate of the upstream intersection after the adjustment is calculated to be less than the threshold; 2.3) Calculate the saturation of each flow direction and determine whether each flow direction is in a saturated state based on the saturation of each flow direction. ① If all traffic directions are not in a saturated state, a preliminary traffic flow diversion plan for the intersections around the construction section is obtained; ② If one of the import flows is in an oversaturated state, first do not change the existing phase plan, and adjust the import lane allocation plan and signal timing to reduce the saturation of the corresponding flow direction; if adjusting the import lane allocation plan and signal timing cannot make the import flow meet the conditions, it is necessary to find the upstream intersection corresponding to the flow direction to limit the flow, and the upstream intersection also needs to re-optimize the timing, lanes or limit the flow of the upstream intersection according to the above method until the saturation of each import flow direction at the upstream intersection is calculated to be less than the threshold; and a preliminary traffic flow guidance and relief plan for the intersections around the construction section is obtained; 2.4) After the preliminary traffic flow diversion plan for the intersections around the construction section has been implemented for a period of time, the traffic flow of the construction section will be reduced step by step according to the above steps until the traffic flow of the construction section is reduced by 100%, and then the construction section will be completely closed; The steps for calculating the adjusted total cycle flow rate ratio Y of the intersection are as follows: (1) Determine the traffic flow rate ratio: In the formula, y i represents the traffic flow rate ratio of each entrance flow direction at the intersection, q i Indicates the traffic flow design data of each entrance flow direction of the intersection, N i Indicates the number of lanes for each entrance flow at the intersection, S i Indicates the saturated flow rate of each inlet flow direction of the intersection; Substituting the traffic flow design data after adjustment of each entrance flow direction at the intersection, the number of lanes and the saturation flow rate of each entrance flow direction into formula (1), the traffic flow rate ratio of each entrance flow direction at the intersection is obtained: q′ nl ,q′ nt They are the design flow data of the north entrance left and straight flow directions after adjustment; q s ' l ,q s ' t are the design flow data of the left and straight flow directions of the south entrance after adjustment; q′ wl ,q′ wt are the design flow data of the left and straight flow directions after adjustment at the west entrance; q′ el ,q′ et They are the design traffic flow data after adjustment for the left and straight flow directions of the east entrance; The number of lanes for left and straight flow at the north entrance of the intersection is N nl 、N n ; The number of lanes for left and straight flow at the south entrance is N sl 、N st ; The number of lanes for left and straight flow at the west entrance is N wl 、N wt ; The number of lanes for left and straight flow at the east entrance is N el 、N et ; Calculate the cycle flow rate ratio: <h2 style=";text-align:left;direction:ltr">Y = ∑y<h2 style=";text-align:left;direction:ltr"> i <h2 style=";text-align:left;direction:ltr"> = max(y1,y2)+max(y3,y4)+max(y5,y6)+max(y7,y8) (2) Where Y represents the total cycle flow rate ratio of an intersection; The specific steps for calculating the saturation of each flow direction are as follows: (1) Calculate the total loss time For the sake of simplicity, the yellow light time A is 3 seconds, the full red time r is 0 seconds, the green light interval time I is 3 seconds, and the start loss time l is 3 seconds; The total loss time L of the cycle is calculated using the formula: (2) Determine the cycle length C: (3) Calculate the total effective green light time G E : G E =∑g ei =C-L (5) (4) Calculate the effective green light time g for each phase ei : (5) Calculate the minimum green light time g min : In the formula, g min is the shortest green light time, dimension is s; L P is the length of the street for pedestrians to cross, with the dimension of m; V P is the walking speed of pedestrians crossing the street, V P It is defined as 1.2m / s; I is the green light interval time, the dimension is s; In order to make the signal timing scheme meet the traffic needs of vehicles and pedestrians at the intersection, the effective green light time g of each phase is ei Must be greater than or equal to the minimum green light time g of each phase mini The solution is g ei Multiply by the adjustment factor f, when g ei ≥g mini When f is 1, when g ei <g mini When f is equal to g mini With g ei The maximum ratio, that is, max(g jmin / g ej ), get the adjusted effective green light duration Further determine the adjusted cycle length C′; (6) Calculate the green light time g for each phase i : (7) Calculate the saturation x of each flow direction i ; In the formula, λ i is the green-to-signal ratio of each flow direction.

2. The method for step-by-step transition adjustment of traffic organization for road full closure construction according to claim 1 is characterized in that: The checkpoint vehicle passing data includes the vehicle passing ID, intersection number, entrance road direction, flow direction, lane number, license plate number, vehicle type, and vehicle passing time; The intersection signal control scheme data includes intersection time period division data, phase scheme design data and intersection signal timing data.

3. The method for step-by-step transition adjustment of traffic organization for road full closure construction according to claim 1 is characterized in that: The steps for obtaining the one-hour traffic flow design data of different inlet flow directions at the intersections around the construction section in step (1) are as follows: ① Obtain the daily vehicle passing data of each entrance direction and time period at the intersections around the construction section within one month; ② Collect statistics on the maximum 15-minute traffic flow data of each entrance flow direction and time period at the intersections around the construction section every day within one month, and add and average the maximum 15-minute traffic flow data of each entrance flow direction and time period in one day: in, It represents the sum of the maximum 15-minute traffic flow data of one import flow direction in one period within a month; ③ Determine the design data of the average one-hour traffic flow at different entrance directions and time periods at the intersections around the construction section:

4. The method for step-by-step transition adjustment of traffic organization for road full closure construction according to claim 1 is characterized in that: The steps to redistribute the reduced traffic flow in the direction leading to the construction section to other directions are as follows: Turn left at the north entrance: q′ nl =(1-α)q nl ; Go straight from the north entrance: Turn right at the north entrance: Turn left at the south entrance: South entrance straight ahead: Turn right at the south entrance: q′ sr =(1-α)q sr ; Turn left at the west entrance: Go straight from the west entrance: q′ wt =(1-α)q wt ; Turn right at the west entrance: Turn left at the east entrance: q′ el =(1-α)q el ; East entrance straight: q′ es =(1-α)q es ; Turn right at the east entrance: q′ er =(1-α)q er ; Among them, q nl ,q nt ,q nr are the design traffic flow data for the left, straight and right directions of the north entrance of the intersection, respectively. sl ,q st ,q s are the design flow data for the left, straight and right directions of the south entrance, respectively, wl ,q wt ,q wr are the design flow data for the left, straight and right directions of the west entrance, respectively, el ,q et ,q er are the design data of traffic flow in the left, straight and right directions of the east entrance respectively; α is the reduction ratio of traffic flow in the construction section; q′ nl ,q′ nt ,q′ nr are the design flow data of the north entrance after adjustment for the left, straight and right flow directions; q′ sl ,q′ st ,q′ sr are the design flow data of the south entrance after adjustment for the left, straight and right flow directions; q′ wl ,q′ wt ,q′ wr are the design flow data of the west entrance after adjustment for the left, straight and right directions; q′ el ,q′ et ,q′ er These are the design traffic flow data after adjustments for the left, straight and right flow directions at the east entrance.

5. The method for step-by-step transition adjustment of traffic organization for road full closure construction according to claim 1 is characterized in that: After a preliminary traffic flow guidance and relief plan for the intersections around the construction section is obtained, it is implemented at the intersections around the construction section for one day. The saturation of the flow directions of each inlet of the surrounding intersections that need to be diverted is calculated in different time periods based on the data of the day. If the saturation is less than the threshold, it meets the requirements. The plan is implemented the next day. If the saturation does not meet the requirements, the traffic flow guidance and relief plan for the intersections around the construction section is updated and adjusted according to the above method based on the data of the day. This process is repeated until the plan is applicable for a period of time. Then a set of traffic flow guidance and relief plans for the surrounding intersections that meet the traffic flow diversion of the construction section can be determined, so that the traffic flow at the intersections around the construction section is balanced.

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