Main signal and pre-signal combined traffic control method for expressway exit ramp and connection intersection

Abstract

The invention discloses an expressway exit ramp and joined intersection main signal and pre-signal combined traffic control method, which comprises the following steps of: firstly, finishing the design of a pre-signal, variable lane and other traffic organization optimization scheme according to the traffic flow characteristics of an expressway exit ramp and an auxiliary road; secondly, completing traffic phase and phase sequence design of the main signal and the pre-signal, determining a control mode of the intersection, and finally establishing a pre-signal traffic signal timing scheme calculation model and a mutual relation model of traffic signal timing of the main signal and the pre-signal; and the traffic capacity maximization of the straight traffic flow of the expressway exit ramp and the connection intersection is realized. According to the invention, the interleaving caused by the simultaneous release of the two traffic flows of the expressway exit ramp and the side road is effectively avoided through the combined control of the main signal and the pre-signal, and the utilization efficiency of space-time resources at the intersection is improved.

Description

Technical Field

[0001] The invention relates to the field of traffic signal control, and in particular to a method for joint passage control of main pre-signals of expressway exit ramps and connecting intersections. Background Art

[0002] This section merely provides background information related to the present disclosure and is not necessarily prior art.

[0003] As the main traffic channel in the city, expressways have the advantages of alleviating the traffic pressure on ground roads and improving the road capacity, which can improve the overall traffic operation efficiency of the city. Urban expressways are connected to ground roads through entrance and exit ramps. Due to the frequent weaving and lane changing of vehicles on the expressway exit ramps and auxiliary roads when passing through the downstream plane connecting intersections, the green light traffic efficiency of the connecting intersections is low and the traffic safety issues are prominent. Expressway exit ramps and connecting intersections often become bottlenecks of urban traffic. The current traffic optimization strategies for expressway exit ramps and connecting intersections include: optimizing the signal timing scheme of connecting intersections, adjusting the number of lanes and lane functions of connecting intersections, and bypassing auxiliary road traffic flows. In general, the existing optimization control strategies have a certain effect on improving the traffic capacity of expressway exit ramps and connecting intersections, but they still cannot avoid the weaving of exit ramp traffic flow and auxiliary road traffic flow or the waste of road time and space resources. Summary of the invention

[0004] Purpose of the invention: In view of the shortcomings of the existing technology, a method for joint traffic control of main pre-signals at expressway exit ramps and connecting intersections is proposed. By reducing the interweaving of traffic at expressway exit ramps and connecting intersections, the traffic capacity of the road section can be improved, thereby optimizing the main signal traffic signal timing plan.

[0005] Technical solution: To achieve the purpose of the present invention, the present invention provides the following technical solution: a method for controlling the main pre-signal of an expressway exit ramp and a connecting intersection, the method comprising the following steps:

[0006] S1: Obtain traffic flow detection data upstream of the expressway exit ramp and upstream of the auxiliary road connecting the intersection.

[0007] S2: In order to reduce the weaving of vehicles on the expressway exit ramp and vehicles on the auxiliary road of the connecting intersection, a pre-signal is added downstream of the exit ramp to achieve the separation of weaving vehicles in terms of travel time, thereby completing the optimization design of the traffic organization plan.

[0008] S3: Based on the traffic organization optimization design plan of the expressway exit ramps and connecting intersections, establish the phase design plan and phase sequence design plan of the expressway exit ramps and connecting intersections.

[0009] S4: Taking the maximum capacity of through traffic at the expressway exit ramp and connecting intersection as the objective function, establish the relationship model between the main signal timing plan and the pre-signal timing plan at the intersection, and determine the calculation model of the main signal timing plan and the pre-signal timing plan based on the traffic data of the expressway exit ramp and connecting intersection. Traffic data includes traffic flow characteristics, road space resources, etc.

[0010] Furthermore, S1 obtains traffic flow detection data upstream of the expressway exit ramp and upstream of the auxiliary road connecting the intersection, including traffic flow, average vehicle speed and turning information.

[0011] A further technical improvement of the present invention is that the specific method of the traffic organization design scheme in step S2 of the present invention is as follows:

[0012] S21: Determine the traffic channelization design scheme for the expressway exit ramp and the connecting intersection: For the four intersecting roads of the connecting intersection, define the entrance road direction where the expressway exit ramp is located as i, and the number of lanes of the entrance road i is 3 or 4 lanes, where the expressway exit ramp is connected to the two inner lanes of the entrance road i, and the rightmost lane is a dedicated right turn lane; define the road where the entrance road i is located as the X direction, and the other opposite road as the Y direction. At a distance L from the stop line of the entrance road ip A pre-signal stop line is set at the exit ramp of the expressway, and the distance from the stop line of the entrance ramp is L i The area is divided into the pre-signal queue area, the lane change area, and the main signal queue area. The length of the pre-signal queue is L ia , the length of the lane change area is L ic , the length of the main signal queue area is L im , then

[0013] L i =L ia +L ic +L im ,L ip =L ic +L im .

[0014] S22: Determine the lane function design plan for the main signal queue area.

[0015] S23: Determine the lane function design plan for the pre-signal queuing area.

[0016] When the number of lanes of the entrance lane i is 4,

[0017] The lane function design scheme of the main signal queue area described in S22 is as follows: the lane numbers from the inner side to the outer side of the main signal queue area are The lane functions are left turn lane Changable lanes Straight lane Right Turn Lane And in the variable lane There is a changeable lane traffic sign ahead.

[0018] The lane function design scheme of the pre-signal queue area described in S23 is as follows: the lane numbers from the inner side to the outer side of the pre-signal queue area are n=1,2,3,4, the lane functions are left turn lanes Go straight and turn right Go straight and turn left Right Turn Lane

[0019] When the number of lanes of the entrance lane i is 3, the lane functions of the pre-signal queue area can be set as left-turn lane, straight-through right-turn lane, straight-through left-turn right-turn lane from the inside to the outside. The vehicles are not controlled by traffic lights, so this scheme has the same control principle and control method as when the number of lanes of the entrance lane i is 4.

[0020] The lane function design scheme of the main signal queue area described in S22 is as follows: the lane numbers from the inner side to the outer side of the main signal queue area are The lane functions are left turn lane Changable lanes Go straight and turn right The left turn lane Control method and left turn lane The control method is the same as that of the variable lane Control method and variable lane The control method is the same as that of the straight-ahead right-turn lane Control method and straight lane The control method is the same.

[0021] The lane function design scheme of the pre-signal queue area described in S23 is as follows: the lane numbers from the inner side to the outer side of the pre-signal queue area are n=1,2,3, the lane functions are left turn lanes Go straight and turn right Go straight, turn left, turn right The left turn lane Control method and left turn lane The control method is the same as that of the straight-ahead right-turn lane Control method of straight-ahead right-turn lane The control method is the same as that of the straight left turn right turn lane Control method for straight-ahead left-turn lane The control method is the same.

[0022] A further technical improvement of the present invention is that the specific method of designing the traffic phase and phase sequence of the connecting intersection in step S3 is as follows:

[0023] S31: Determine the main signal phase and phase sequence scheme for the expressway intersection:

[0024] The cycle time of the expressway connecting the intersection is C. The intersection has 6 phases in total. Phases 1, 2, 3, and 4 are defined as the Y-direction main signal straight phase, the Y-direction main signal left-turn phase, the X-direction main signal straight phase, and the X-direction main signal left-turn phase. The corresponding phase travel time is g1, g2, g4, and g5 respectively. i,s , g i,l (including yellow light duration); C = g1 + g2 + g i,s +g i,l .

[0025] In period 1, T1 is the initial time of the main signal of the intersection. At T1, the straight phase (Phase 1) of the entrance traffic light in the Y direction is turned on and lasts for g1 time.

[0026] In period 2, at time T1+g1, phase 1 ends, and the left turn phase (phase 2) of the traffic light on the entrance road in the Y direction lasts for g2 time.

[0027] Period 3, T1+g1+g2, phase 2 ends, the straight phase (phase 3) of the traffic light on the entrance road in the X direction is turned on, the vehicles on the main signal straight lane of the entrance road i pass, and the left-turning vehicles queue up and wait, and the duration is g. i,s Duration.

[0028] Period 4, T1+g1+g2+g i,s At time 1, phase 3 ends, the left turn phase (phase 4) of the traffic light on the entrance road in the X direction is turned on, and vehicles in the main left turn lane of the entrance road i pass, and vehicles going straight queue up and wait for g. i,l Duration.

[0029] T1+g1+g2+g i,s +g i,l At this moment, the traffic in phase 4 ends and the next traffic signal control cycle begins, repeating periods 1 to 4 until the traffic control stops.

[0030] S32: Determine the pre-signal phase and phase sequence scheme for the expressway intersection:

[0031] The pre-signal queue area performs lane signal control, and defines phase 5 as the pre-signal queue area straight-through right-turn lane Pass, Phase 6 is the pre-signal queue area straight ahead left turn lane The corresponding phase passage time is g i,a1 , g i,a2 (including yellow light duration); left turn lane in pre-signal queue area and right turn lane Not controlled by traffic lights. C = g i,a1 +g i,a2 .

[0032] Period 1, T2 is the initial time of the intersection pre-signal. At T2, the variable lane in the main signal queue area of ​​entrance lane i Switch to the through lane, the through right turn lane in the pre-signal queue area Passing, i.e. phase 5, in which through vehicles enter the main signal through lane and right-turning vehicles enter the main signal right-turn lane for passing.

[0033] Period 2, T2+g i,a1 At this time, phase 5 is completed, and the main signal queue area of ​​entrance lane i is changeable Switch to the left turn lane, go straight ahead in the pre-signal queue area and enter the left turn lane Passing, i.e. phase 6, in which through vehicles enter the main signal through lane and left-turning vehicles enter the main signal left-turn lane.

[0034] T2+g i,a1 +g i,a2 At this moment, phase 6 traffic ends and enters the next traffic signal control cycle, repeating periods 1 and 2 until traffic control stops.

[0035] S4: The further technical improvement of the present invention is that the relationship between the main signal timing scheme and the pre-signal timing scheme of the intersection in step S4 of the present invention, and the specific method of the signal timing calculation method are as follows:

[0036] S41: Determine the relationship between the main signal timing plan and the pre-signal timing plan of the intersection: In order to ensure the safe operation of the main signal queue area, all vehicles entering the variable lane should be able to be released before the variable lane in the main signal queue area switches lane function. The relationship between the main signal timing plan and the pre-signal timing plan of the intersection is as follows:

[0037] Rule 1, T2+g i,a1 +g i,a2 At this moment, the pre-signal phase 6 traffic ends, the next cycle phase 5 traffic starts, and the main signal queue area of ​​entrance lane i becomes a variable lane The left-turn lane switches to the through lane. At this moment, the vehicle that leaves the pre-signal stop line should leave the intersection before the main signal X direction left turn phase (phase 4) ends when traveling at the average speed.

[0038]

[0039] Right now

[0040] in is the average vehicle speed.

[0041] Rule 2, T2+g i,a1 At this moment, the pre-signal phase 5 has ended, and the main signal queue area of ​​entrance lane i can be changed into a lane The vehicle that switches from the through lane to the left turn lane at this moment and leaves the pre-signal stop line should leave the intersection before the main signal X direction through phase (phase 3) ends when traveling at the average speed.

[0042]

[0043] Right now

[0044] in is the average vehicle speed.

[0045] Combining rule 1 and rule 2, the relationship between the main signal timing plan and the pre-signal timing plan is:

[0046]

[0047] The function max() takes the larger value.

[0048] Pick Maximize intersection traffic efficiency.

[0049] S42: Further, the main signal timing scheme for the expressway connecting intersection is determined, which can be calculated by the Webster method.

[0050] S43: Further, determine the pre-signal timing plan for the expressway connecting intersection: In order to ensure that the through traffic flow of the expressway exit ramp and the connecting intersection passes with maximum efficiency during the through phase (phase 3) of the main signal of the entrance lane i in the X direction, it is necessary to further determine the traffic signal timing plan of the pre-signal.

[0051] S431, determining relevant parameters and parameter relationships.

[0052] Due to lane signal control in the pre-signal queue area, the pre-signal queue area is the straight and right turn lane (Phase 5) and pre-signal queue area through left turn lane (Phase 6) Alternate release, straight ahead right turn lane and left turn lane All straight-moving vehicles in the intersection must pass through the intersection within the X-direction main signal straight-moving phase (phase 3). To achieve the highest traffic capacity of the pre-signal, the straight-moving right-turn lane released by the pre-signal within the signal cycle Vehicles and left turn lane Vehicles The following formula should be satisfied:

[0053]

[0054] in Pre-signal straight ahead and right turn lanes and left turn lane The average number of vehicles released per signal cycle, Pre-signal straight ahead and right turn lanes and left turn lane Average hourly traffic volume (pcu / h).

[0055] According to the distance L between the main signal stop line and the pre-signal stop line of the entrance lane i in the X direction ip , we can calculate L ip The maximum number of vehicles that can be accommodated during the straight phase in the section for:

[0056]

[0057] in is the average queue spacing in the stationary state of the straight phase of the main signal of the entrance lane i in the X direction, is the average vehicle length.

[0058] S432, discuss and determine the solution according to the situation. During the Y direction main signal straight phase (phase 1) and left turn phase (phase 2), vehicles exiting the pre-signal stop line must queue in the main signal queue area and wait for the green light to be released in the X direction straight phase (phase 3). That is, according to the distance L between the main signal stop line and the pre-signal stop line of the entrance lane i in the X direction, ip Maximum number of vehicles that can be accommodated The through and right turn lanes released by the pre-signal within the signal cycle Number of through vehicles released The relationship between the straight and right turn lanes in the pre-signal queue area can be further determined. Signal duration g of the passing phase (phase 5) i,a1 , λ1 is the straight-ahead right-turn lane Number of vehicles released The proportion of vehicles going straight.

[0059] Case 1: When the straight right turn lane is released by the pre-signal within the signal cycle The number of straight-moving vehicles is greater than that of L ip The maximum number of vehicles that can be accommodated in the interval is hour,

[0060] Description: When the green light starts to be released in the straight phase (phase 3) of the X direction, the straight right turn lane in the pre-signal queue area within the signal cycle Some vehicles that should be released cannot pass the pre-signal stop line because the queue ahead is full. They need to continue passing for a while during the X-direction straight phase (phase 3). in is the average saturated headway time of the straight phase (phase 3) in the X direction, then the relationship between the main signal timing scheme and the pre-signal timing scheme of the intersection should satisfy:

[0061]

[0062] Right now

[0063] According to S32,

[0064] Where δ is the travel loss time.

[0065] According to S41, the relationship between T1 and T2 should satisfy:

[0066]

[0067] Case 2: When the straight right turn lane is released by the pre-signal within the signal cycle The number of straight-moving vehicles is smaller than that of L ip The maximum number of vehicles that can be accommodated in the interval is hour,

[0068] Description: When the green light starts to be released in the straight phase (phase 3) of the X direction, the straight right turn lane in the pre-signal queue area within the signal cycle If the number of vehicles leaving the pre-signal stop line exceeds the number of vehicles that should be released, the pre-signal queue area will be the straight left turn lane. (Phase 6) The released vehicles cannot completely pass through the intersection in this cycle. The straight-going vehicles that have not passed through wait in the main signal queue area for the next signal cycle. At this time, the straight-going right-turn lane in the pre-signal queue area The signal passing time of the passing phase (phase 5) is:

[0069]

[0070] Go straight and turn left The signal duration of the passing phase (phase 6) is:

[0071]

[0072] According to S41, the relationship between T1 and T2 should satisfy:

[0073]

[0074] To ensure the variable lanes in the main signal queue area of ​​the entrance road i Traffic efficiency, pre-signal queue area straight right turn lane All vehicles going through should exit the intersection before the X-direction main signal through phase (phase 3) ends, to avoid vehicles going through staying when the variable lane switches to the left-turn lane. Therefore, the distance between the main signal stop line and the pre-signal stop line of the X-direction entrance lane i should meet the following requirements:

[0075]

[0076] The principle of the present invention is: when the number of lanes of the expressway exit ramp and the auxiliary road is small and it is impossible to set left-turn and straight-through lanes respectively, or setting left-turn and straight-through lanes respectively on the expressway exit ramp and the auxiliary road will cause waste of road time and space resources, a pre-signal and a variable lane are set in front of the connection between the expressway exit ramp and the auxiliary road, and the traffic organization design scheme and the traffic phase sequence design scheme of the exit ramp and the connecting intersection are optimized to achieve the separation of the traffic flow of the expressway exit ramp and the auxiliary road in time and space to avoid vehicle interweaving, and according to the data such as the traffic flow characteristics of the expressway exit ramp and the connecting intersection, the traffic signal control scheme of the connecting intersection is further optimized to achieve the joint control of the expressway exit ramp and the connecting intersection, and effectively improve the traffic capacity of the intersection.

[0077] Compared with the prior art, the present invention has the following significant advantages:

[0078] The present invention provides a main and pre-signal joint traffic control method for expressway exit ramps and connecting intersections. By setting a pre-signal in front of the connection between the expressway exit ramp and the auxiliary road, the main and pre-signal joint control method is adopted to effectively avoid the interweaving caused by the simultaneous release of two traffic flows of the expressway exit ramp and the auxiliary road, thereby improving the safety of traffic operation at the intersection; by setting a variable lane in the main signal queuing area, the utilization efficiency of the intersection space resources is improved.

[0079] On the basis of the signal timing scheme for connecting intersections, an optimization model for the pre-signal traffic signal timing scheme was established with the highest traffic efficiency of expressway exit ramps and connecting intersections as the objective function, which improved the traffic operation capacity of expressway exit ramps and connecting intersections. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0081] Figure 1 This is a schematic diagram of the traffic organization channelization scheme for the expressway exit ramp and connecting intersection under this method;

[0082] Figure 2 This is a schematic diagram of the relationship between the main signal control scheme and the pre-signal control scheme at an intersection.

[0083] Figure 3 This is the main signal phase sequence scheme of this scheme.

[0084] Figure 4 This is the pre-signal phase sequence scheme of this scheme. DETAILED DESCRIPTION

[0085] In order to deepen the understanding of the present invention, the technical solution of the present invention will be further described in detail below in conjunction with the drawings in the embodiments. This embodiment is only used to explain the present invention and does not constitute a limitation on the protection scope of the present invention.

[0086] The following is a description of the main pre-signal combined traffic control method for expressway exit ramps and connecting intersections in conjunction with the accompanying drawings and specific embodiments, including the following steps:

[0087] S1: Obtain traffic flow detection data upstream of the expressway exit ramp and upstream of the auxiliary road connecting the intersection.

[0088] S2: In order to reduce the weaving of vehicles on the expressway exit ramp and vehicles on the auxiliary road of the connecting intersection, a pre-signal is added downstream of the exit ramp to achieve the separation of weaving vehicles in terms of travel time, thereby completing the optimization design of the traffic organization plan.

[0089] S3: Based on the traffic organization optimization design plan of the expressway exit ramps and connecting intersections, establish the phase design plan and phase sequence design plan of the expressway exit ramps and connecting intersections.

[0090] S4: Taking the highest traffic efficiency of through traffic at expressway exit ramps and connecting intersections as the objective function, a relationship model between the main signal timing plan and the pre-signal timing plan at the intersection is established, and the calculation model of the main signal timing plan and the pre-signal timing plan is determined based on the traffic flow characteristics, road space resources and other data of expressway exit ramps and connecting intersections.

[0091] like Figure 1 As shown, the specific method of the traffic organization design scheme in step S2 is as follows:

[0092] S21: Determine the traffic channelization design plan for the expressway exit ramp and the connecting intersection: For the four intersecting roads of the connecting intersection, define the entrance road direction where the expressway exit ramp is located as i, and the number of lanes of the entrance road i is 3 or 4 lanes, where the expressway exit ramp is connected to the two inner lanes of the entrance road i, and the rightmost lane is a dedicated right turn lane; define the road where the entrance road i is located as the X direction, and the other opposite road as the Y direction. At a distance L from the stop line of the entrance road ip A pre-signal stop line is set at the exit ramp of the expressway, and the distance from the stop line of the entrance ramp is L i The area is divided into the pre-signal queue area, the lane change area, and the main signal queue area. The length of the pre-signal queue is L ia , the length of the lane change area is L ic , the length of the main signal queue area is L im , then

[0093] L i =L ia +L ic +L im ,L ip =L ic +L im , unit is m.

[0094] S22: Determine the lane function design plan for the main signal queue area.

[0095] S23: Determine the lane function design plan for the pre-signal queuing area.

[0096] When the number of lanes of the entrance lane i is 4,

[0097] The lane function design scheme of the main signal queue area described in S22 is as follows: the lane numbers from the inner side to the outer side of the main signal queue area are n=1,2,3,4, the lane functions are left turn lanes Changable lanes Straight lane Right Turn Lane And in the variable lane There is a changeable lane traffic sign ahead.

[0098] The lane function design scheme of the pre-signal queue area described in S23 is as follows: the lane numbers from the inner side to the outer side of the pre-signal queue area are n=1,2,3,4, the lane functions are left turn lanes Go straight and turn right Go straight and turn left Right Turn Lane

[0099] When the number of lanes of the entrance lane i is 3, the lane functions of the pre-signal queue area can be set as left-turn lane, straight-through right-turn lane, straight-through left-turn right-turn lane from the inside to the outside. The vehicles are not controlled by traffic lights, so this scheme has the same control principle and control method as when the number of lanes of the entrance lane i is 4.

[0100] The lane function design scheme of the main signal queue area described in S22 is as follows: the lane numbers from the inner side to the outer side of the main signal queue area are n=1,2,3, the lane functions are left turn lanes Changable lanes Go straight and turn right The left turn lane Control method and left turn lane The control method is the same as that of the variable lane Control method and variable lane The control method is the same as that of the straight-ahead right-turn lane Control method and straight lane The control method is the same.

[0101] The lane function design scheme of the pre-signal queue area described in S23 is as follows: the lane numbers from the inner side to the outer side of the pre-signal queue area are n=1,2,3, the lane functions are left turn lanes Go straight and turn right Go straight, turn left, turn right The left turn lane Control method and left turn lane The control method is the same as that of the straight-ahead right-turn lane Control method of straight-ahead right-turn lane The control method is the same as that of the straight left turn right turn lane Control method for straight-ahead left-turn lane The control method is the same.

[0102] The specific method of designing the traffic phase and phase sequence of the connecting intersection in step S3 is as follows ( Figure 2 shown):

[0103] S31: Determine the main signal phase and phase sequence scheme for the expressway intersection:

[0104] The cycle time of the expressway connecting the intersection is C. The intersection has 6 phases in total. Phases 1, 2, 3, and 4 are defined as the Y-direction main signal straight phase, the Y-direction main signal left-turn phase, the X-direction main signal straight phase, and the X-direction main signal left-turn phase. The corresponding phase travel time is g1, g2, g4, and g5 respectively.i,s , g i,l (including yellow light duration); where C = g1+g2+g i,s +g i,l , the unit of travel time and cycle time is s.

[0105] In period 1, T1 is the initial time of the main signal of the intersection. At T1, the straight phase (Phase 1) of the entrance traffic light in the Y direction is turned on and lasts for g1 time.

[0106] In period 2, at time T1+g1, phase 1 ends, and the left turn phase (phase 2) of the traffic light on the entrance road in the Y direction lasts for g2 time.

[0107] Period 3, T1+g1+g2, phase 2 ends, the straight phase (phase 3) of the traffic light on the entrance road in the X direction is turned on, the vehicles on the main signal straight lane of the entrance road i pass, and the left-turning vehicles queue up and wait, and the duration is g. i,s Duration.

[0108] Period 4, T1+g1+g2+g i,s At time 1, phase 3 ends, the left turn phase (phase 4) of the traffic light on the entrance road in the X direction is turned on, and vehicles in the main left turn lane of the entrance road i pass, and vehicles going straight queue up and wait for g. i,l Duration.

[0109] T1+g1+g2+g i,s +g i,l At this moment, the traffic in phase 4 ends and the next traffic signal control cycle begins, repeating periods 1 to 4 until the traffic control stops.

[0110] Main signal phase sequence design scheme see Figure 3 .

[0111] S32: Determine the pre-signal phase and phase sequence scheme for the expressway intersection:

[0112] The pre-signal queue area performs lane signal control, and defines phase 5 as the pre-signal queue area straight-through right-turn lane Pass, Phase 6 is the pre-signal queue area straight ahead left turn lane The corresponding phase passage time is g i,a1 , g i,a2 (including yellow light duration); left turn lane in pre-signal queue area and right turn lane Not controlled by traffic lights, C = g i,a1 +g i,a2 .

[0113] Period 1, T2 is the initial time of the intersection pre-signal. At T2, the variable lane in the main signal queue area of ​​entrance lane i Switch to the through lane, the through right turn lane in the pre-signal queue area Passing, i.e. phase 5, in which through vehicles enter the main signal through lane and right-turning vehicles enter the main signal right-turn lane for passing.

[0114] Period 2, T2+g i,a1 At this time, phase 5 is completed, and the main signal queue area of ​​entrance lane i is changeable Switch to the left turn lane, go straight ahead in the pre-signal queue area and enter the left turn lane Passing, i.e. phase 6, in which through vehicles enter the main signal through lane and left-turning vehicles enter the main signal left-turn lane.

[0115] T2+g i,a1 +g i,a2 At this moment, phase 6 traffic ends and enters the next traffic signal control cycle, repeating periods 1 and 2 until traffic control stops.

[0116] Pre-signal phase sequence design scheme see Figure 4 .

[0117] The relationship between the main intersection signal timing scheme and the pre-signal timing scheme in step S4 of the present invention, as well as the specific method of the signal timing calculation method are as follows:

[0118] S41: Determine the relationship between the main signal timing plan and the pre-signal timing plan of the intersection: In order to ensure the safe operation of the main signal queue area, all vehicles entering the variable lane should be able to be released before the variable lane in the main signal queue area switches lane function. The relationship between the main signal timing plan and the pre-signal timing plan of the intersection is as follows:

[0119] Rule 1, T2+g i,a1 +g i,a2 At this moment, the pre-signal phase 6 traffic ends, the next cycle phase 5 traffic starts, and the main signal queue area of ​​entrance lane i becomes a variable lane The left-turn lane switches to the through lane. At this moment, the vehicle that leaves the pre-signal stop line should leave the intersection before the main signal X direction left turn phase (phase 4) ends when traveling at the average speed.

[0120]

[0121] Right now

[0122] in is the average vehicle speed in m / s.

[0123] Rule 2, T2+gi,a1 At this moment, the pre-signal phase 5 has ended, and the main signal queue area of ​​entrance lane i can be changed into a lane The vehicle that switches from the through lane to the left turn lane at this moment and leaves the pre-signal stop line should leave the intersection before the main signal X direction through phase (phase 3) ends when traveling at the average speed.

[0124]

[0125] Right now

[0126] in is the average vehicle speed in m / s.

[0127] Combining rule 1 and rule 2, the relationship between the main signal timing plan and the pre-signal timing plan is:

[0128]

[0129] The function max() takes the larger value;

[0130] Pick Maximize intersection traffic efficiency.

[0131] S42: Determine the main signal timing plan for the expressway connecting intersection, which can be calculated by the Webster method.

[0132] S43: Determine the pre-signal timing plan for the expressway connecting intersection: In order to ensure that the through traffic flow of the expressway exit ramp and the connecting intersection passes with maximum efficiency during the through phase (phase 3) of the main signal of the entrance lane i in the X direction, it is necessary to further determine the traffic signal timing plan of the pre-signal.

[0133] Lane signal control is performed in the pre-signal queue area. The straight and right turn lanes in the pre-signal queue area (Phase 5) and pre-signal queue area through left turn lane (Phase 6) Alternate release, straight ahead right turn lane and left turn lane All straight vehicles must pass through the intersection within the X-direction main signal straight phase (phase 3). To achieve the highest traffic efficiency of the pre-signal, the straight right turn lane released by the pre-signal within the signal cycle Vehicles and left turn lane Vehicles The following formula should be satisfied:

[0134]

[0135] in Pre-signal straight ahead and right turn lanes and left turn lane The average number of vehicles released per signal cycle, Pre-signal straight ahead and right turn lanes and left turn lane The average hourly traffic volume, in pcu / h, where pcu is the standard vehicle equivalent.

[0136] According to the distance L between the main signal stop line and the pre-signal stop line of the entrance lane i in the X direction ip , calculate L ip The maximum number of vehicles that can be accommodated during the straight phase in the section for:

[0137]

[0138] is the average queue spacing in the stationary state of the straight phase of the main signal of the entrance lane i in the X direction, in meters, is the average vehicle length in meters, where the average queue spacing refers to the minimum spacing between the front and rear vehicles when the vehicles are queued in a stationary state.

[0139] S432, discuss and determine the solution according to the situation. During the Y direction main signal straight phase (phase 1) and left turn phase (phase 2), vehicles exiting the pre-signal stop line must queue in the main signal queue area and wait for the green light to be released in the X direction straight phase (phase 3). That is, according to the distance L between the main signal stop line and the pre-signal stop line of the entrance lane i in the X direction, ip Maximum number of vehicles that can be accommodated The through and right turn lanes released by the pre-signal within the signal cycle Number of through vehicles released The relationship between the straight and right turn lanes in the pre-signal queue area can be further determined. Signal duration g of the passing phase (phase 5) i,a1 , λ1 is the straight-ahead right-turn lane Number of vehicles released The proportion of vehicles going straight.

[0140] Case 1: When the straight right turn lane is released by the pre-signal within the signal cycle The number of straight-moving vehicles is greater than that of L ip The maximum number of vehicles that can be accommodated in the interval is hour,

[0141] Description: When the green light starts to be released in the straight phase (phase 3) of the X direction, the straight right turn lane in the pre-signal queue area within the signal cycle Some vehicles that should be released cannot pass the pre-signal stop line because the queue ahead is full. They need to continue passing for a while during the X-direction straight phase (phase 3). is the average saturated headway in the straight phase (phase 3) in the X direction. The saturated headway is the time difference between the front and rear vehicles passing the stop line under the vehicle saturation state, and the unit is s. The relationship between the main signal timing scheme and the pre-signal timing scheme of the intersection should satisfy:

[0142]

[0143] Right now

[0144] According to S32,

[0145] Where δ is the travel loss time, in seconds. According to S41, the relationship between T1 and T2 should satisfy:

[0146]

[0147] Case 2: When the straight right turn lane is released by the pre-signal within the signal cycle The number of straight-moving vehicles is smaller than that of L ip The maximum number of vehicles that can be accommodated in the interval is hour,

[0148] When the green light starts to be released in the straight phase (phase 3) of the X direction, the straight right turn lane in the pre-signal queue area within the signal cycle If the number of vehicles leaving the pre-signal stop line exceeds the number of vehicles that should be released, the pre-signal queue area will be the straight left turn lane. (Phase 6) The released vehicles cannot completely pass through the intersection in this cycle. The straight-going vehicles that have not passed through wait in the main signal queue area for the next signal cycle. At this time, the straight-going right-turn lane in the pre-signal queue area The signal duration of the passing phase (phase 5) is:

[0149]

[0150] Go straight and turn left The signal duration of the passing phase (phase 6) is:

[0151]

[0152] According to S41, the relationship between T1 and T2 satisfies:

[0153]

[0154] Ensure variable lanes in the main signal queue area of ​​the entrance lane i Traffic efficiency, pre-signal queue area straight right turn lane All vehicles going through should exit the intersection before the X-direction main signal through phase (phase 3) ends, to avoid vehicles going through staying when the variable lane switches to the left-turn lane. Therefore, the distance between the main signal stop line and the pre-signal stop line of the X-direction entrance lane i should meet the following requirements:

[0155] Right now

[0156] Since the present invention does not involve the adjustment of the traffic signal timing scheme of the main signal of the intersection, the following takes the entrance lane i as an example, and analyzes the change of the vehicle interweaving phenomenon of the entrance lane by implementing the combined traffic control method of the expressway exit ramp and the main pre-signal of the connecting intersection, including the following steps:

[0157] For the four intersecting roads connecting the intersections, define the entrance road direction where the expressway exit ramp is located as i, and the number of lanes of the entrance road i is 4. The intersection traffic organization plan is designed according to S2, and the traffic phase and phase sequence design plan is carried out according to S3.

[0158] The expressway exit ramp and the connecting intersection have a total of 6 phases, and phases 1, 2, 3, and 4 are defined as the Y-direction main signal straight phase, the Y-direction main signal left turn phase, the X-direction main signal straight phase, and the X-direction main signal left turn phase, respectively. According to the traffic flow in each direction of the intersection, the cycle length of the expressway connecting intersection is calculated by the Webster method as C = 100s, and the travel time of each phase is g1 = 30s, g2 = 20s, g4 = 30s, g5 = 40s, g6 = 50s, g7 = 60s, g8 = 70s, g9 = 80s, g10 = 80s, g11 = 80s, g12 = 80s, g13 = 80s, g14 = 80s, g15 = 80s, g16 = 80s, g17 = 80s, g18 = 80s, g19 = 90s, g20 = 90s, g21 = 90s, g22 = 90s, g23 = 90s, g24 = 90s, g25 = 90s, g26 = 90s, g27 = 90s, g28 = 90s, g29 = 90s, g30 = 90s, g31 = 90s, g32 = 90s, g33 = 90s, g34 = 90s i,s =30s, g i,l =20s (including yellow light duration);

[0159] The distance L between the main signal stop line and the pre-signal stop line of the entrance road i ip =48m, average distance in static state Average vehicle length Average vehicle speed Saturated headway The travel loss time δ = 3s. According to S431, L ip The maximum number of straight-moving vehicles that can be accommodated during the straight-moving phase within the section

[0160] The pre-signaled straight-through right-turn lane and left turn lane The average hourly traffic volume is The straight right turn lane The proportion of through traffic flow in the released traffic flow is λ1=0.7, and the through left turn lane The proportion of through traffic flow in the released traffic flow is λ2=0.7, so the pre-signaled through right turn lane Average number of through vehicles released per signal cycle According to S432 Case 2,

[0161]

[0162] The relationship between the initial time of the main signal and the initial time of the pre-signal of the inlet channel i is:

[0163]

[0164] At the same time, when the main signal of the entrance lane i is in the left turn phase, the variable lane is in the left turn phase, which can improve the traffic efficiency of the left-turn traffic flow, and is particularly suitable for expressway exit ramps and connecting intersections with large left-turn traffic volume.

[0165] For the intersection with 4 lanes in the entrance lane i, the conventional traffic organization scheme generally has the functions of left-turn lane, through lane, through lane, and right-turn lane from the inside to the outside. When using the conventional scheme, the average number of right-turning vehicles that need to change lanes on the expressway exit ramp per signal cycle is The average number of left-turning vehicles that need to weave lane changes on the auxiliary road per signal cycle is Moreover, they need to change lanes twice, and the interweaving lane-changing vehicles will cause obvious traffic conflicts with the straight-moving vehicles, reducing the traffic capacity of the road section and increasing vehicle delays.

[0166] By adopting the combined traffic control method of the main pre-signal of the expressway exit ramp and the connecting intersection provided by the present invention, the traffic flow of the expressway exit ramp and the auxiliary road traffic flow can be isolated in time to avoid interweaving, and the traffic signal timing plan can simultaneously meet the traffic needs of the expressway exit ramp and the auxiliary road traffic flow.

[0167] The present invention provides a method and idea for a combined traffic control method for main pre-signal of an expressway exit ramp and a connecting intersection. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A method for joint traffic control of main pre-signals at expressway exit ramps and connecting intersections, characterized in that: The following steps are involved: S1: Obtain traffic flow detection data upstream of the expressway exit ramp and upstream of the auxiliary road connecting the intersection; S2: Based on the data obtained in S1, weaving vehicles are separated at the travel time by adding a pre-signal downstream of the exit ramp to form an optimized design of the traffic organization plan; S3: Based on the traffic organization optimization design scheme of the expressway exit ramp and connecting intersection obtained in S2, establish the phase design scheme and phase sequence design scheme of the expressway exit ramp and connecting intersection; S4: Taking the maximum capacity of through traffic at the expressway exit ramps and connecting intersections as the objective function, a relationship model between the main signal timing plan and the pre-signal timing plan at the intersection is established, and the calculation model of the main signal timing plan and the pre-signal timing plan is determined based on the traffic data of the expressway exit ramps and connecting intersections.

2. The method for controlling the main pre-signal of the expressway exit ramp and the connecting intersection according to claim 1 is characterized in that: S1 obtains traffic flow detection data upstream of the expressway exit ramp and upstream of the auxiliary road connecting the intersection, including traffic flow, average vehicle speed and turning information.

3. The method for controlling the main pre-signal of the expressway exit ramp and the connecting intersection according to claim 2 is characterized in that: The specific methods of traffic organization design in S2 include: S21: Determine the traffic channelization design plan for the expressway exit ramp and the connecting intersection, the connecting intersection includes 4 crossroads, define the entrance road direction where the expressway exit ramp is located as i, wherein the expressway exit ramp is connected to the two inner lanes of the entrance road i, and the rightmost lane is a right-turn lane; define the road where the entrance road i is located as the X direction, and the other opposite road as the Y direction; at a distance of L from the stop line of the entrance road ip A pre-signal stop line is set at the exit ramp of the expressway, and the distance from the stop line of the entrance ramp is L i The area is divided into the pre-signal queue area, the lane change area, and the main signal queue area. The length of the pre-signal queue is L ia , the pre-signal queue, the lane change area length is L ic , the length of the main signal queue area is L im , then L i =L ia +L ic +L im ,L ip =L ic +L im ; S22: Determine the lane function design plan for the main signal queue area; S23: Determine the lane function design plan for the pre-signal queuing area.

4. The method for controlling the main pre-signal of the expressway exit ramp and the connecting intersection according to claim 3 is characterized in that: The number of lanes of the entrance lane i is 4. The lane function design scheme of the main signal queue area described in S22 is as follows: the lane numbers from the inner side to the outer side of the main signal queue area are n=1,2,3,4, the lane functions are left turn lanes Changable lanes Straight lane Right Turn Lane The lane function design scheme of the pre-signal queue area described in S23 is as follows: the lane numbers from the inner side to the outer side of the pre-signal queue area are n=1,2,3,4, the lane functions are left turn lanes Go straight and turn right Go straight and turn left Right Turn Lane 5. The method for controlling the main pre-signal of the expressway exit ramp and the connecting intersection according to claim 4 is characterized in that: The number of lanes of the entrance lane i is 3. The lane function design scheme of the main signal queue area described in S22 is as follows: the lane numbers from the inner side to the outer side of the main signal queue area are n=1,2,3, the lane functions are left turn lanes Changable lanes Go straight and turn right The left turn lane Control method and left turn lane The control method is the same as that of the variable lane Control method and variable lane The control method is the same as that of the straight-ahead right-turn lane Control method and straight lane The control method is the same; The lane function design scheme of the pre-signal queue area described in S23 is as follows: the lane numbers from the inner side to the outer side of the pre-signal queue area are n=1,2,3, the lane functions are left turn lanes Go straight and turn right Go straight, turn left, turn right The left turn lane Control method and left turn lane The control method is the same as that of the straight-ahead right-turn lane Control method of straight-ahead right-turn lane The control method is the same as that of the straight left turn right turn lane Control method for straight-ahead left-turn lane The control method is the same.

6. The method for controlling the main pre-signal of the expressway exit ramp and the connecting intersection according to claim 4 or 5, characterized in that: The specific steps of the phase design and phase sequence design of the expressway exit ramp and connecting intersection in S3 include: S31: Determine the main signal phase and phase sequence plan for the expressway intersection. The cycle time of the expressway connecting intersection is C. The intersection includes 6 phases. Phases 1, 2, 3, and 4 are defined as the Y-direction main signal straight phase, the Y-direction main signal left-turn phase, the X-direction main signal straight phase, and the X-direction main signal left-turn phase. The corresponding phase travel time is g1, g2, g4, and g5 respectively. i,s , g i,l , the passage time includes the green light time and the yellow light time; where C = g1 + g2 + g i,s +g i,l ; Period 1, with T1 as the initial time of the main signal of the intersection, at T1, the straight phase (phase 1) of the entrance traffic light in the Y direction is turned on and lasts for g1 time; Period 2, at time T1+g1, phase 1 traffic ends, and the left turn phase (phase 2) of the traffic light on the entrance road in the Y direction lasts for g2 duration; Period 3, T1+g1+g2, phase 2 ends, the straight phase (phase 3) of the traffic light on the entrance road in the X direction is turned on, the vehicles on the main signal straight lane of the entrance road i pass, and the left-turning vehicles queue up and wait, and the duration is g. i,s Duration; Period 4, T1+g1+g2+g i,s At time 1, phase 3 ends, the left turn phase (phase 4) of the traffic light on the entrance road in the X direction is turned on, and vehicles in the main left turn lane of the entrance road i pass, and vehicles going straight queue up and wait for g. i,l Duration; T1+g1+g2+g i,s +g i,l At this moment, the traffic in phase 4 ends and the next traffic signal control cycle begins, repeating periods 1 to 4 until the traffic control stops; S32: Determine the pre-signal phase and phase sequence scheme for the expressway intersection. The pre-signal queue area performs lane signal control, and defines phase 5 as the pre-signal queue area straight-through right-turn lane Pass, Phase 6 is the pre-signal queue area straight ahead left turn lane The corresponding phase passage time is g i,a1 , g i,a2 , the passage time includes the green light time and the yellow light time; Pre-signal queue area left turn lane and right turn lane Not controlled by traffic lights, C = g i,a1 +g i,a2 ; Period 1, T2 is the initial time of the intersection pre-signal. At T2, the variable lane in the main signal queue area of ​​entrance lane i Switch to the through lane, the through right turn lane in the pre-signal queue area Passing, i.e. phase 5, in which through vehicles enter the main signal through lane and right-turning vehicles enter the main signal right-turn lane for passing; Period 2, T2+g i,a1 At this time, phase 5 is completed, and the main signal queue area of ​​entrance lane i is changeable Switch to the left turn lane, go straight ahead in the pre-signal queue area and enter the left turn lane Passing, i.e., phase 6, in which through vehicles enter the main signal through lane and left-turning vehicles enter the main signal left-turn lane; T2+g i,a1 +g i,a2 At this moment, phase 6 traffic ends and enters the next traffic signal control cycle, repeating periods 1 and 2 until traffic control stops.

7. The method for controlling the main pre-signal of the expressway exit ramp and the connecting intersection according to claim 6 is characterized in that: The relationship between the main signal timing scheme and the pre-signal timing scheme of the intersection in S4, as well as the specific method of signal timing calculation are as follows: S41: Determine the relationship between the main signal timing plan and the pre-signal timing plan of the intersection; S42: Determine the main signal timing plan for the intersection connecting the expressway; S43: Determine the pre-signal timing plan for the expressway intersection.

8. The method for controlling the main pre-signal of the expressway exit ramp and the connecting intersection according to claim 7 is characterized in that: The relationship between the main signal timing plan and the pre-signal timing plan of the intersection described in S41 is as follows: Before the variable lane in the main signal queue area switches lane function, all vehicles entering the variable lane should be released. The relationship between the main signal timing plan and the pre-signal timing plan of the intersection is as follows: Rule 1, T2+g i,a1 +g i,a2 At this moment, the pre-signal phase 6 traffic ends, the next cycle phase 5 traffic starts, and the main signal queue area of ​​entrance lane i becomes a variable lane The left-turn lane switches to the through lane. At this moment, the vehicle that leaves the pre-signal stop line should leave the intersection before the main signal X direction left turn phase (phase 4) ends when traveling at the average speed. Right now in is the average speed of vehicles; Rule 2, T2+g i,a1 At this moment, the pre-signal phase 5 has ended, and the main signal queue area of ​​entrance lane i can be changed into a lane The vehicle that switches from the through lane to the left turn lane at this moment and leaves the pre-signal stop line should leave the intersection before the main signal X direction through phase (phase 3) ends when traveling at the average speed. Right now in is the average speed of vehicles; Combining rule 1 and rule 2, the relationship between the main signal timing plan and the pre-signal timing plan is: The function max() takes the larger value; Pick Maximize intersection traffic efficiency.

9. The method for controlling the main pre-signal of the expressway exit ramp and the connecting intersection according to claim 8, characterized in that: The main signal timing plan for the expressway intersection is calculated and determined by the Webster method.

10. The method for controlling the main pre-signal combined traffic of the expressway exit ramp and the connecting intersection according to claim 9, characterized in that: The steps of the pre-signal timing scheme for the expressway intersection described in S43 are as follows: S431, determining relevant parameters and parameter relationships; Pre-signal queue area straight ahead right turn lane (Phase 5) and pre-signal queue area through left turn lane (Phase 6) Alternate release, straight ahead right turn lane and left turn lane All straight-moving vehicles must pass through the intersection within the X-direction main signal straight-moving phase (phase 3), and the straight-moving right-turn lane released by the pre-signal within the signal cycle Vehicles and left turn lane Vehicles Satisfy the following formula: in Pre-signal straight ahead and right turn lanes and left turn lane The average number of vehicles released per signal cycle, Pre-signal straight ahead and right turn lanes and left turn lane Average hourly traffic volume; According to the distance L between the main signal stop line and the pre-signal stop line of the entrance lane i in the X direction ip , calculate L ip The maximum number of vehicles that can be accommodated during the straight phase in the section for: in is the average queue spacing in the stationary state of the straight phase of the main signal of the entrance lane i in the X direction, is the average vehicle length; S432, discuss and determine the plan according to the situation; Case 1: When the straight right turn lane is released by the pre-signal within the signal cycle The number of straight-moving vehicles is greater than that of L ip The maximum number of vehicles that can be accommodated in the interval is , where λ1 is the straight-ahead right-turn lane Number of vehicles released The proportion of vehicles going straight, When the X-direction straight phase (Phase 3) starts to be released, the straight right turn lane in the pre-signal queue area within the signal cycle Some vehicles that should be released cannot pass the pre-signal stop line because the queue ahead is full. They need to continue passing for a while during the X-direction straight phase (phase 3). in is the average saturated headway time of the straight phase (phase 3) in the X direction, then the relationship between the main signal timing scheme and the pre-signal timing scheme of the intersection satisfies: Right now According to S32, Where δ is the travel loss time; At the same time, according to S41, the relationship between T1 and T2 satisfies: Case 2: When the straight right turn lane is released by the pre-signal within the signal cycle The number of straight-moving vehicles is smaller than that of L ip The maximum number of vehicles that can be accommodated in the interval is hour, When the X-direction straight phase (Phase 3) starts to be released, the straight right turn lane in the pre-signal queue area within the signal cycle If the number of vehicles leaving the pre-signal stop line exceeds the number of vehicles that should be released, the pre-signal queue area will be the straight left turn lane. (Phase 6) The vehicles released for passing cannot completely pass through the intersection in this cycle. The straight-going vehicles that have not passed through wait in the main signal queue area for the next signal cycle. At this time, the straight-going right-turn lane in the pre-signal queue area The signal passing time of the passing phase (phase 5) is: Go straight and turn left The signal duration of the passing phase (phase 6) is: According to S41, the relationship between T1 and T2 satisfies: The distance between the main signal stop line and the pre-signal stop line of the entrance lane i in the X direction meets the following requirements: Ensure variable lanes in the main signal queue area of ​​the entrance lane i Traffic efficiency, pre-signal queue area straight right turn lane All vehicles going straight out of the intersection must exit before the X-direction main signal straight phase (Phase 3) ends.

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