Intersection operation optimization evaluation method

Abstract

The invention discloses an intersection operation optimization evaluation method, which comprises the following steps: on the basis of a balanced distribution principle, studying and judging the overall traffic load degree of an intersection, the balance degree of each flow direction of an opposite inlet and the balance degree of the internal flow direction of the inlet according to the flow rate ratio of each flow direction of the intersection, and proposing an intersection channelization transformation necessity analysis model; decision basis is provided for channelization transformation, variable guide lane setting and lap joint phase setting, the necessity of intersection optimization is accurately evaluated, the intersection performance cannot be effectively improved, and urban congestion cannot be effectively relieved.

Description

Technical Field

[0001] The invention relates to the technical field of traffic safety, and in particular to an intersection operation optimization evaluation method. Background Art

[0002] As the urbanization process continues to accelerate, traffic congestion has gradually become one of the important factors restricting urban development. Signalized intersections are a complex integrated transportation system formed by the interaction, influence and restriction of multiple factors. Due to the rapid growth of traffic volume, more and more intersections have become bottlenecks for urban traffic. The smoothness of intersections plays a key role in the operating efficiency of the entire road network. Urban traffic congestion is often prominent at intersections, so the reasonable setting of markings on each section of the intersection is crucial.

[0003] Data shows that at present, a single indicator is mostly used to conduct qualitative evaluation of the service status of signalized intersections, and there is a lack of comprehensive evaluation indicators of multiple intersection traffic status for quantitative evaluation of signalized intersections, resulting in inaccurate evaluation results of traffic status and unclear boundaries; when evaluating intersections, there is a lack of consideration of intersection differences and time differences. For example, the weights of various evaluation indicators in the evaluation system of different intersections are different, and the service status of the same intersection during peak and off-peak periods is different. It is difficult to accurately assess the necessity of intersection optimization, and it is impossible to effectively improve intersection performance and alleviate urban congestion.

[0004] Chinese patent document CN115909732A discloses a "method for evaluating the stability of straight-moving vehicles at intersections". It includes the following parts: parameter initialization, obtaining the time series of headway time of straight-moving vehicles, phase space reconstruction, Lyapunov stability analysis, outlier removal and outlier rate calculation. The data required by this evaluation method is only the headway time series of straight-moving vehicles. The above technical solution cannot effectively evaluate the necessity of intersection channelization. Summary of the invention

[0005] The present invention mainly solves the technical problem that the original technical solution cannot effectively evaluate the necessity of intersection channelization, and provides an intersection operation optimization evaluation method. Based on the principle of balanced distribution and according to the flow rate ratio of each flow direction at the intersection, the overall traffic load of the intersection, the balance degree of each flow direction of the opposite entrance and the balance degree of the internal flow direction of the entrance are judged, and a necessity analysis model for intersection channelization reconstruction is proposed, which provides a decision-making basis for channelization reconstruction, variable guide lane setting and overlap phase setting, accurately evaluates the necessity of intersection optimization, effectively improves intersection performance and alleviates urban congestion.

[0006] The above technical problem of the present invention is mainly solved by the following technical solution: The present invention comprises the following steps: S1. Set the number of days for data acquisition , obtain the historical parameters of the analysis period and intersection; S2. Obtain the average hourly traffic demand data of each flow direction during the judgment period, obtain the average saturated flow of each flow direction during the judgment period, calculate the traffic demand and headway of each flow direction during the judgment period used for the final judgment, and calculate the flow rate ratio of each flow direction during the judgment period based on the traffic demand and headway of each flow direction to reflect the traffic load level of each flow direction; S3. Calculate the flow balance coefficients of the east-west imports and the north-south imports, and traverse all imports to calculate the internal flow balance coefficients of imports; S4. Analyze the imbalance of east-west imports, north-south imports and internal import flows, and determine the direction of improvement; S5. Comprehensively output process information and improvement plans for the improvement direction of north-south and east-west imports.

[0007] As a preferred embodiment, the step S1 specifically includes obtaining the judgment period The intersection history parameters include intersection channelization information, the number of through lanes at each entrance, and the number of left-turn lanes.

[0008] Preferably, the arrangement S1 further includes setting different historical data fusion modes: like , then for the previous Days data, before acquisition The traffic demand data of each direction and the real-time headway data of the target intersection in Tianzhong during the judgment period are the same as the current common problems. Day data; like , then directly take the previous The traffic demand data of each direction at the target intersection during the daily data analysis period, and the real-time headway data.

[0009] Preferably, the step S2 includes converting the periodic traffic demand data of each flow direction in each day's judgment period into hourly traffic demand data, and averaging them to obtain the first Average hourly traffic demand data for each flow direction during the day .

[0010] As a preferred embodiment, the step S2 includes obtaining the saturated flow data of each flow direction during the period of each day of the frequent problem analysis. , assuming that the flow direction is Effective saturation flow data , calculate the average saturated flow rate of each flow direction during the judgment period :

[0011] Calculate saturated headway using saturated flow :

[0012] If there is no real-time saturation flow data, , In order to configure the configuration parameters of the straight and left-turn headway, the saturated flow rate of each inlet and each flow direction is calculated.

[0013] Preferably, the step S2 includes calculating the traffic demand and headway time in each flow direction judgment period used for the final judgment:

[0014]

[0015] in, For traffic demand, that is, intersection import Flow direction transportation needs; is the saturated headway; if the data fusion method is selected , then the average number of days is .

[0016] Preferably, the step S2 includes calculating the flow rate ratio of each direction in the judgment period according to the traffic demand of each direction and the headway, the flow rate ratio being the ratio of the traffic demand of the direction to the saturated flow rate of the direction, reflecting the traffic load level of each direction:

[0017]

[0018] in, is the saturation flow rate, i.e., the inlet Flow direction The saturation flow rate; is the flow rate ratio, i.e., the inlet Flow direction flow rate ratio.

[0019] Preferably, the step S3 specifically includes: Calculate the counter-flow balance coefficient of the east-west imports and obtain import 1, that is, the straight flow rate ratio of the east import , left turn flow rate ratio , then obtain the straight flow rate ratio of inlet 3, that is, the west inlet , left turn flow rate ratio ; Flow direction There is an opposite flow direction. and , then the east-west import flow The counterflow balance coefficient is:

[0020] If flow direction j has no opposite flow direction or there is flow direction at the opposite inlet, it is considered as missing data. or , then the east-west import flow The counterflow balance coefficient is 0; Calculate the counterflow balance coefficient of the north-south inlet and obtain the inlet 2, that is, the straight flow rate ratio of the south inlet , left turn flow rate ratio , then obtain the straight flow rate ratio of inlet 4, i.e. the north inlet , left turn flow rate ratio .

[0021] Flow direction There is an opposite flow direction. and , then the north-south import flow The counterflow balance coefficient is:

[0022] Flow direction If there is no opposite flow or there is flow at the opposite inlet, the data is considered missing. or , then the north-south import flow The counterflow balance coefficient is 0, which is the default balance.

[0023] from Start traversing all imports and calculate the internal flow balance coefficient of the imports The value of the balance coefficient is in the range of [0,1]. The larger the value of the balance coefficient, the greater the difference in the flow rate ratio of the inlet internal flow direction. The calculation formula is as follows:

[0024] If imported If there is a flow direction, it is judged that the data is missing or there is only one flow direction inside. or , the internal flow balance coefficient is 0, which is the default balance.

[0025] As a preference, the step S4 specifically comprises: recording the opposite inlets with unbalanced opposite flows as a set ; The imports with internal flow imbalance are recorded as a set ; like , that is, there are no imports with imbalanced opposite flows, nor are there imports with imbalanced internal flows, and it is judged as "retaining the existing channelization and optimizing the timing."

[0026] like , that is, there are no opposite imports with imbalanced opposite flows, but there are imports with imbalanced internal flows, which are discussed based on the quantity and distribution of imbalanced imports; If the collection There is only one element in , that is, only one import has an internal flow imbalance, and the import traffic organization optimization or channelization transformation in set B is judged as "traffic organization optimization".

[0027] If the collection There are 2 elements in , that is, there is an internal flow imbalance between the two imports, and the judgment is "retain the existing channelization and optimize the timing"; like , that is, the opposite inlet has flow imbalance, but there is no internal flow imbalance in the inlet. The inlet in set A adopts overlapping phase and is judged as "adopting overlapping phase"; like , that is, the imports with opposite flow imbalance and internal flow imbalance, the set Import traffic organization optimization or channelization transformation in the project is judged as "traffic organization optimization"; in, is the east-west import flow balance coefficient, is the north-south import flow balance coefficient, is the inlet internal flow balance coefficient, is the intersection imbalance threshold, is the flow imbalance threshold.

[0028] Preferably, the step S5 specifically includes, for the north-south opposite import and the east-west opposite import: If the judgment results of the two groups of opposite imports are both "keep the existing channelization and optimize the timing", the timing optimization will be started; If at least one pair of opposite imports is judged as "traffic organization optimization" or "increase overlapping phase": the judgment conclusion is output for the imports judged as "traffic organization optimization"; the overlapping phase is recommended and output for the opposite imports judged as "increase overlapping phase".

[0029] The beneficial effects of the present invention are as follows: based on the principle of balanced distribution and according to the flow rate ratio of each flow direction at the intersection, the overall traffic load of the intersection, the balance degree of each flow direction of the opposite entrance and the balance degree of the flow direction inside the entrance are judged, and a necessity analysis model for intersection channelization reconstruction is proposed, which provides a decision-making basis for channelization reconstruction, variable guide lane setting and overlapping phase setting, accurately evaluates the necessity of intersection optimization, effectively improves intersection performance and alleviates urban congestion. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1It is a channelized evaluation flow chart of the present invention.

[0031] Figure 2 It is a flow direction analysis and judgment flow chart of the present invention.

[0032] Figure 3 It is a schematic diagram of different flow directions at an intersection of the present invention. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the technical solutions of the present application are further described in detail below through embodiments and in combination with the accompanying drawings. It should be understood that the specific implementation method described here is only an optimal embodiment of the present application, which is only used to explain the present application and does not limit the protection scope of the present application. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] Parameter Explanation : The time when frequently occurring problems start, and also the time when the research and judgment period starts : Frequently asked questions are over, and it is also the end time of the research period. :Cause analysis algorithm judgment period : The number of days for obtaining historical data, the default is 30 days :Historical data fusion method, When D is used, only the number of days with frequent problem judgments during the judgment period within D days is taken data, When , take the relevant data of the previous D days' research and judgment period.

[0035] import : The entrance of the intersection , by default, import 1 is the east import, import 2 is the south import, import 3 is the west import, and import 4 is the north import; Flow direction :Direction of imports, For straight flow, Left turn flow Transportation Demand : Junction import Flow direction Transportation needs

[0036] Saturation flow rate :import Flow direction Saturation flow rate

[0037] Headway : Configuration parameters, flow direction Headway , For straight flow, Left turn flow Saturation flow :import Flow direction The saturation flow is calculated based on the data of the target intersection last month. The current frequency is 1 hour. :import Flow direction The headway time of the vehicle is based on the saturated flow Calculated Number of lanes : Configuration parameters, import Flow direction Number of lanes Flow rate ratio :import Flow direction Flow rate ratio; East-West import flow balance coefficient : Characterizes the balance degree of flow rate ratio between left-turning and straight-through flow at east-west inlets; North-South import flow balance coefficient : Indicates the balance degree of flow rate ratio between left-turning and straight-through flow directions at north-south inlets; Import internal flow balance coefficient : Characterizes the balance degree of flow rate ratio between left-turn and straight flow in the same inlet; Traffic demand data missing threshold : Configuration parameters, the missing ratio threshold of traffic demand data, the default value is 0.5; Intersection imbalance threshold : Configuration parameters, critical value of intersection traffic load level, the default value is 0.9; Flow imbalance threshold : Configuration parameters, flow rate ratio imbalance critical value, the default value is 0.2; Algorithm Output Output: intersection id, time period, classification result, detailed description of the classification result, time of analysis, traffic demand ratio of each direction at the intersection ( etc.), hourly traffic demand of each direction at the intersection during the analysis period ( etc.), each inlet internal flow balance coefficient , determine the headway time of each direction within the time period .

[0038] 1. Classification results include: Timing optimization: It is recommended to keep the existing channelization and optimize the timing.

[0039] Traffic organization optimization. It is recommended to optimize traffic organization or transform it into a channel.

[0040] Phase overlap recommendation. It is recommended to use overlap phase.

[0041] 2. Specific description of classification results: Timing optimization: Output judgment conclusion: It is recommended to retain the existing channelization and optimize the timing.

[0042] Traffic organization optimization: Conclusion: Inlet 1 is internally unbalanced, and the flow in the left-turning direction is much greater than the straight-ahead flow. It is recommended to channelize the inlet.

[0043] Internal imbalance imports: such as import 1, import 2.

[0044] Specific situation of unbalanced inlet: If inlet 1 is internally unbalanced, the flow rate ratio of the left-turn flow direction is much greater than that of the straight-ahead flow direction.

[0045] Phase overlap recommendation: Judgment conclusion: It is recommended to use overlapping phase.

[0046] Oppositely unbalanced import pair: For example, imports 1 and 2 have relative flow imbalance.

[0047] Inlets that require overlapping phases: If the relative flow directions of inlets 1 and 2 are unbalanced, inlet 1 needs to be overlapped.

[0048] Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow charts describe the operations (or steps) as sequential processes, many of the operations (or steps) therein can be implemented in parallel, concurrently, or simultaneously. In addition, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but can also have additional steps not included in the drawings; the process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0049] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0050] Embodiment: A method for optimizing intersection operation evaluation in this embodiment is as follows: Figure 1 , Figure 2 As shown, the following steps are included: Step 1: Get the analysis period , historical data acquisition days , intersection channelization information, parameters such as the number of through lanes and left-turn lanes at each entrance; Step 2: Obtain different relevant historical data according to different fusion methods: Case 1: If , then for the previous Days data, before acquisition The traffic demand data of each direction and the real-time headway data of the target intersection in Tianzhong are obtained for the days when the problem is the same as the current common problem. Day data.

[0051] Case 1: If , then directly take the previous The traffic demand data of each direction at the target intersection during the daily data analysis period, and the real-time headway data.

[0052] Step 3: Convert the periodic traffic demand data of each direction in each day’s judgment period into hourly traffic demand data and calculate the average to obtain the first Average hourly traffic demand data for each flow direction during the day : Assume that there is a total of valid periodic traffic demand data during the analysis period , The period length corresponding to the period is :

[0053] in For the Imported Flow direction During the judging period Neidi Traffic demand data for valid periods Step 4: Obtain saturated flow data for each direction during the analysis period of each day for common problems (Unit: ), assuming that the flow direction is Effective saturation flow data (Saturated flow data is based on a frequency of 1 hour) Calculate the average saturated flow in each direction during the assessment period :

[0054] Calculate saturated headway using saturated flow :

[0055] If there is no real-time saturation flow data, ( For configuration parameters, configure the straight and left turn headway) to calculate the saturated flow rate of each inlet and each flow direction ( ) Step 5: Calculate the traffic demand and headway time for each flow direction in the final judgment period (if the data fusion method is selected , then the average number of days is :

[0056]

[0057] Step 6: Calculate the flow rate ratio of each direction within the judgment period based on the traffic demand of each direction and the headway. The flow rate ratio is the ratio of the traffic demand of the direction to the saturated flow rate of the direction, reflecting the traffic load level of each direction:

[0058]

[0059] Step 7: Calculate the counterflow balance coefficient of the east-west imports and obtain the straight flow rate ratio of import 1 (east import) , left turn flow rate ratio , and then obtain the straight flow rate ratio of inlet 3 (west inlet) , left turn flow rate ratio .

[0060] Case 1: Flow direction There is an opposite flow direction. and , then the east-west import flow The counterflow balance coefficient is:

[0061] Case 2: Flow direction j has no opposite flow direction or the opposite inlet has flow direction, which is considered as missing data. or , then the east-west import flow The counterflow balance coefficient is 0; Step 8: Calculate the flow balance coefficient of the north-south inlet and obtain the straight flow rate ratio of inlet 2 (south inlet) , left turn flow rate ratio , and then obtain the straight flow rate ratio of inlet 4 (north inlet) , left turn flow rate ratio .

[0062] Case 1: Flow direction There is an opposite flow direction. and , then the north-south import flow The counterflow balance coefficient is:

[0063] Case 2: Flow direction If there is no opposite flow or there is flow at the opposite inlet, the data is considered missing. or , then the north-south import flow The counterflow balance coefficient is 0, which is the default balance. Step 9: From Start traversing all imports and calculate the internal flow balance coefficient of the imports The value of the balance coefficient is in the range of [0,1]. The larger the value of the balance coefficient, the greater the difference in the flow rate ratio of the inlet internal flow direction. The calculation formula is as follows:

[0064] If imported If there is a flow direction, it is judged that the data is missing or there is only one flow direction inside. or , the internal flow balance coefficient is 0, which is the default balance.

[0065] Step 10: Analyze the imbalance of east-west import flows and the imbalance of internal import flows, and then determine the improvement plan. ; The imports with internal flow imbalance are recorded as a set ; Case 1: , that is, there are no imports with imbalanced opposite flows, nor are there imports with imbalanced internal flows, and it is judged as "retaining the existing channelization and optimizing the timing."

[0066] Case 2: , that is, there are no opposite imports with imbalanced opposite flows, but there are imports with imbalanced internal flows, which are discussed based on the quantity and distribution of imbalanced imports; Case2.1: Collection There is only one element in , that is, only one import has an internal flow imbalance, and the import traffic organization optimization or channelization transformation in set B is judged as "traffic organization optimization".

[0067] Case2.2: Collection There are 2 elements in , that is, there is an internal flow imbalance between the two imports, and the judgment is "retain the existing channelization and optimize the timing"; Case 3: , that is, the opposite inlet has flow imbalance, but there is no internal flow imbalance in the inlet. The inlet in set A adopts overlapping phase and is judged as "adopting overlapping phase"; Case 4: , that is, the imports with opposite flow imbalance and internal flow imbalance, the set Import traffic organization optimization or channelization transformation in the project is judged as "traffic organization optimization"; Step 11: Analyze the imbalance of north-south import flows and the imbalance of internal import flows. The specific steps are the same as Step 7, and then proceed to Step 9.

[0068] Step 12: Output the intersection ID, time period, classification results, specific description of the classification results, the time of judgment, and the flow rate ratio of each direction at the intersection ( etc.), each inlet internal flow balance coefficient , the average hourly traffic demand of each direction at the intersection during the analysis period ( etc.), and determine the average headway time of each direction during the period .

[0069] Specific instructions for classification results: For north-south and east-west imports, if the assessment results of both groups of imports are "retain existing channelization and optimize timing", the timing optimization algorithm module will be entered.

[0070] For north-south and east-west opposite imports, if at least one pair of opposite imports is judged as "traffic organization optimization" or "increase overlap phase": 1. Judgment conclusion of import output judged as "traffic organization optimization": Conclusion: Inlet 1 is internally unbalanced, and the flow in the left-turning direction is much greater than the straight-ahead flow. It is recommended to channelize the inlet.

[0071] Internal imbalance imports: such as import 1, import 2.

[0072] Specific situation of unbalanced inlet: If inlet 1 is internally unbalanced, the flow rate ratio of the left-turn flow direction is much greater than that of the straight-ahead flow direction.

[0073] 2. For the opposite inlet judged as "increase overlap phase", enter the overlap phase recommendation algorithm module and output: Judgment conclusion: It is recommended to use overlapping phase.

[0074] Oppositely unbalanced import pair: For example, imports 1 and 2 have relative flow imbalance.

[0075] Inlets that require overlapping phases: If the relative flow directions of inlets 1 and 2 are unbalanced, inlet 1 needs to be overlapped.

[0076] Table 1 Real-time traffic parameters

[0077] Table 2 Algorithm configuration parameters Example 1

[0078] Step 1: Get the analysis period , historical data acquisition days , intersection channelization information, parameters such as the number of through lanes and left-turn lanes at each entrance; The analysis period is [8:00,9:00], the historical data is taken from day 5, and the intersection channelization information is as shown in the following table.

[0079] Table 3 Intersection channelization information table

[0080] Step 2: Obtain different relevant historical data according to different fusion methods: Case 1: If , then for the previous Days data, before acquisition The traffic demand data of each direction and the real-time headway data of the target intersection in Tianzhong are obtained for the days when the problem is the same as the current common problem. Day data.

[0081] Case 1: If , then directly take the previous The traffic demand data of each direction at the target intersection during the daily data analysis period, and the real-time headway data.

[0082] The fusion method in this case is , directly take the front The traffic demand data of each direction at the target intersection during the daily data analysis period, and the real-time headway data.

[0083] Step 3: Convert the periodic traffic demand data of each direction in each day’s judgment period into hourly traffic demand data and calculate the average to obtain the first Average hourly traffic demand data for each flow direction during the day : Assume that there is a total of valid periodic traffic demand data during the analysis period , The period length corresponding to the period is :

[0084] in For the Imported Flow direction During the judging period Neidi Traffic demand data for a valid period.

[0085] The traffic demand data for the through flow at the east entrance of the intersection on the first day during the effective period of 8:00-9:00 during the analysis period are shown in the following table.

[0086] Table 4 Traffic demand data table

[0087]

[0088] Through calculation, we can get the traffic demand of the direct flow on the first day of the east import. It is 166pcu / h.

[0089] Step 4: Obtain saturated flow data for each direction during the analysis period of each day for common problems (Unit: ), assuming that the flow direction is Effective saturation flow data (Saturated flow data is based on a frequency of 1 hour) Calculate the average saturated flow data for each flow direction during the analysis period , calculate the saturated headway time by saturated flow :

[0090] If there is no real-time saturation flow data, ( For configuration parameters, configure the straight and left turn headway) to calculate the saturated flow rate of each inlet and each flow direction ( ) There were 5 valid data on the straight saturated flow at the east entrance during the analysis period of 8:00-9:00 on the first day.

[0091] Table 5 Valid data table

[0092]

[0093]

[0094] Step 5: Calculate the traffic demand and headway time of each flow direction used for the final judgment: The effective traffic demand for direct travel from the east to the west during the historical 5-day analysis period of 8:00-9:00.

[0095] Table 6 Effective traffic demand table

[0096] Effective traffic demand data for direct traffic from the east

[0097] The saturated headway data of the east-bound straight vehicles during the historical 5-day analysis period of 8:00-9:00.

[0098] Table 7 Straight saturation headway data table

[0099] Average saturated headway time of east import straight

[0100] Step 6: Calculate the flow rate ratio of each direction within the judgment period based on the traffic demand of each direction and the headway. The flow rate ratio is the ratio of the traffic demand of the direction to the saturated flow rate of the direction, reflecting the traffic load level of each direction: East inlet straight saturation flow rate

[0101] East inlet straight flow rate ratio

[0102] Repeat the calculation steps of Step 1- Step 6 above to obtain the traffic hourly demand and saturation flow rate of each direction at the intersection during the historical 5-day data analysis period of 8:00-9:00 as follows: Table 8 Traffic hourly demand and saturation flow rate table

[0103] According to the calculation steps of Step 1- Step 6, we can get: East inlet straight flow rate ratio

[0104] East inlet left turn flow rate ratio

[0105] Similarly, the straight flow rate of the south entrance of the intersection is is 0.3, the left turn flow rate ratio is 0.3; Intersection west entrance straight flow rate ratio is 0.1, the left turn flow rate ratio is 0.1; Intersection north entrance straight flow rate ratio is 0.13, the left turn flow rate ratio is 0.35; Step 7: Calculate the counterflow balance coefficient of the east-west imports and obtain the straight flow rate ratio of import 1 (east import) , left turn flow rate ratio , and then obtain the straight flow rate ratio of inlet 3 (west inlet) , left turn flow rate ratio .

[0106] Case 1: Flow direction There are opposite flows and east-west import flows The counterflow balance coefficient is:

[0107]

[0108] Through the formula we can get , , the east-west import flows are balanced and no adjustment is needed.

[0109] Step 8: Calculate the flow balance coefficient of the north-south inlet and obtain the straight flow rate ratio of inlet 2 (south inlet) , left turn flow rate ratio , and then obtain the straight flow rate ratio of inlet 4 (north inlet) , left turn flow rate ratio .

[0110] Case 1: Flow direction There is an opposite flow direction and a north-south import flow direction The counterflow balance coefficient is:

[0111]

[0112] Step 9: From Start traversing all imports and calculate the internal flow balance coefficient of the imports The value of the balance coefficient is in the range of [0,1]. The larger the value of the balance coefficient, the greater the difference in the flow rate ratio of the inlet internal flow direction. If there is a flow direction that is missing data or there is only one flow direction inside, the internal flow direction balance coefficient is 0, and the default balance is used.

[0113]

[0114]

[0115]

[0116]

[0117] Step 10: Analyze the imbalance in east-west import flows and internal import flows, and determine improvement plans.

[0118] The opposite inlets with unbalanced opposite flows are recorded as a set ; The imports with internal flow imbalance are recorded as a set ; Case 1: , that is, there are no imports with imbalanced opposite flows, nor are there imports with imbalanced internal flows, and it is judged as "retaining the existing channelization and optimizing the timing."

[0119] Case 2: , that is, there are no opposite imports with imbalanced opposite flows, but there are imports with imbalanced internal flows, which are discussed based on the quantity and distribution of imbalanced imports; Case2.1: Collection There is only one element in the set, that is, there is only one import with internal flow imbalance. The import traffic organization optimization or channelization transformation in set B is judged as "traffic organization optimization".

[0120] Case2.2: Collection There are two elements in it, namely, there is an internal flow imbalance at the two imports, and it is judged as "retaining the existing channelization and optimizing the timing"; Case 3: , that is, the opposite inlet has flow imbalance, but there is no internal flow imbalance in the inlet. The inlet in set A adopts overlapping phase and is judged as "adopting overlapping phase"; Case 4: , that is, the imports with opposite flow imbalance and internal flow imbalance, the set Import traffic organization optimization or channelization transformation in the project is judged as "traffic organization optimization"; Step 11: Analyze the imbalance of north-south import flows and the imbalance of internal import flows. The specific steps are the same as Step 7, and then proceed to Step 9.

[0121] The default value is 0.2, which can be obtained through research and judgment. , , belongs to Case 2.1, for That is, traffic organization is optimized at the northern import.

[0122] Step 12: Output the intersection ID, time period, classification results, specific description of the classification results, the time of judgment, and the flow rate ratio of each direction at the intersection ( etc.), each inlet internal flow balance coefficient , the average hourly traffic demand of each direction at the intersection during the analysis period ( etc.), and determine the average headway time of each direction during the period

[0123] Specific instructions for classification results: For north-south and east-west imports, if the assessment results of both groups of imports are "retain existing channelization and optimize timing", the timing optimization algorithm module will be entered.

[0124] For north-south and east-west opposite imports, if at least one pair of opposite imports is judged as "traffic organization optimization" or "increase overlap phase": 1. Judgment conclusion of import output judged as "traffic organization optimization": Conclusion: Inlet 1 is internally unbalanced, and the flow in the left-turning direction is much greater than the straight-ahead flow. It is recommended to channelize the inlet.

[0125] Internal imbalance imports: such as import 1, import 2.

[0126] Specific situation of unbalanced inlet: If inlet 1 is internally unbalanced, the flow rate ratio of the left-turn flow direction is much greater than that of the straight-ahead flow direction.

[0127] 2. For the opposite inlet judged as "increase overlap phase", enter the overlap phase recommendation algorithm module and output: Judgment conclusion: It is recommended to use overlapping phase.

[0128] Oppositely unbalanced import pair: For example, imports 1 and 2 have relative flow imbalance.

[0129] Inlet that needs to overlap phase: if the relative flow direction of inlet 1 and 2 is unbalanced, inlet 1 needs to overlap phase. Final output result: Conclusion: The north inlet is internally unbalanced, and the flow in the left-turning direction is much greater than the straight-through flow. It is recommended to channelize the inlet. Internal imbalance imports: Imports from the north; Specific situation of unbalanced import: The north import is internally unbalanced, and the flow rate ratio of the left-turn flow is much greater than that of the straight flow.

[0130] Example 2 The traffic flow at a certain intersection during the morning peak period of 8:00-9:00 is analyzed, and the basic traffic flow information is as follows: Table 9 Basic information table of traffic flow

[0131] The intersection channelization information is as follows: Table 10 Traffic hourly demand and saturation flow rate table

[0132] According to the calculation steps of Step 1- Step 6, we can get: East inlet straight flow rate ratio

[0133] East inlet left turn flow rate ratio

[0134] Similarly, the straight flow rate of the west entrance of the intersection is 0.1, left turn flow rate at west entrance is 0.1; Intersection south entrance straight flow rate ratio 0.1, left turn flow rate ratio is 0.31; Intersection north entrance straight flow rate ratio 0.1, left turn flow rate ratio is 0.1; Step 7: Calculate the counterflow balance coefficient of the east-west imports and obtain the straight flow rate ratio of import 1 (east import) , left turn flow rate ratio , and then obtain the straight flow rate ratio of inlet 3 (west inlet) , left turn flow rate ratio .

[0135] Case 1: Flow direction There are opposite flows and east-west import flows The counterflow balance coefficient is:

[0136]

[0137] Step 8: Calculate the flow balance coefficient of the north-south inlet and obtain the straight flow rate ratio of inlet 2 (south inlet) , left turn flow rate ratio , and then obtain the straight flow rate ratio of inlet 4 (north inlet) , left turn flow rate ratio .

[0138] Case 1: Flow direction There is an opposite flow direction and a north-south import flow direction The counterflow balance coefficient is:

[0139]

[0140] Calculations show that there is an imbalance in the left-turning flow direction of north-south imports.

[0141] Step 9: From Start traversing all imports and calculate the internal flow balance coefficient of the imports The value of the balance coefficient is in the range of [0,1]. The larger the value of the balance coefficient, the greater the difference in the flow rate ratio of the inlet internal flow direction. If there is a flow direction that is missing data or there is only one flow direction inside, the internal flow direction balance coefficient is 0, and the default balance is used.

[0142]

[0143]

[0144]

[0145] 0.1-0.1=0 Through calculation, it can be found that the straight and left-turn flows inside the south entrance are unbalanced.

[0146] Step 10: Analyze the imbalance in east-west import flows and internal import flows, and determine improvement plans.

[0147] The opposite inlets with unbalanced opposite flows are recorded as a set ; The imports with internal flow imbalance are recorded as a set ; Case 1: , that is, there are no imports with imbalanced opposite flows, nor are there imports with imbalanced internal flows, and it is judged as "retaining the existing channelization and optimizing the timing."

[0148] Case 2: , that is, there are no opposite imports with imbalanced opposite flows, but there are imports with imbalanced internal flows, which are discussed based on the quantity and distribution of imbalanced imports; Case2.1: Collection There is only one element in the set, that is, there is only one import with internal flow imbalance. The import traffic organization optimization or channelization transformation in set B is judged as "traffic organization optimization".

[0149] Case2.2: Collection There are two elements in it, namely, there is an internal flow imbalance at the two imports, and it is judged as "retaining the existing channelization and optimizing the timing"; Case 3: , that is, the opposite inlet has flow imbalance, but there is no internal flow imbalance in the inlet. The inlet in set A adopts overlapping phase and is judged as "adopting overlapping phase"; Case 4: , that is, the imports with opposite flow imbalance and internal flow imbalance, the set Import traffic organization optimization or channelization transformation in the project is judged as "traffic organization optimization"; Step 11: Analyze the imbalance of north-south import flows and the imbalance of internal import flows. The specific steps are the same as Step 7, and then proceed to Step 9.

[0150] The default value is 0.2, which can be obtained through research and judgment. , , belongs to Case 4.

[0151] Step 12: Output the intersection ID, time period, classification results, specific description of the classification results, the time of judgment, and the flow rate ratio of each direction at the intersection ( etc.), each inlet internal flow balance coefficient , the average hourly traffic demand of each direction at the intersection during the analysis period ( etc.), and determine the average headway time of each flow direction during the time period

[0152] Specific explanation of the classification results: For north-south and east-west imports, 1. If the results of the analysis of the two groups of opposite imports are both "retain the existing channelization and optimize the timing", enter the timing optimization algorithm module.

[0153] 2. If at least one pair of opposite imports is judged as "traffic organization optimization" or "increase overlap phase", the output judgment of the import judged as "traffic organization optimization" is: 2.1 Conclusion: Inlet 1 is internally unbalanced, and the flow in the left-turn direction is much greater than the flow in the straight direction. It is recommended to channelize the inlet 2.2 Internal imbalance import: such as import 1, import 2 2.3 Specific situation of unbalanced inlet: If the inlet 1 is internally unbalanced, the flow rate ratio of the left-turn flow direction is much greater than that of the straight-ahead flow direction.

[0154] 3. For the opposite inlet judged as "increase overlap phase", enter the overlap phase recommendation algorithm module and output: 3.1 Conclusion: It is recommended to use overlapping phase 3.2 Opposite unbalanced import pairs: For example, imports 1 and 2 have a relative flow imbalance 3.3 Inlet that needs overlapping phase: If the relative flow direction of inlet 1 and 2 is unbalanced, inlet 1 needs overlapping phase Final output: 1. Conclusion: The southern inlet is internally unbalanced, and the flow in the left-turning direction is much greater than the flow in the straight-through direction. It is recommended to channelize the inlet; Internal imbalance imports: Imports from the South; Specific situation of unbalanced import: The south import is internally unbalanced, and the flow rate ratio of the left-turn flow is much greater than that of the straight flow.

[0155] 2. Conclusion: It is recommended to use overlapping phase; Opposite imbalance import pair: North-south imports are relatively unbalanced with a left turn flow Specific situation of unbalanced imports: The left-turn flow direction of north-south imports is unbalanced, and the south imports need to overlap the phase.

[0156] The specific embodiments described herein are merely examples of the spirit of the present invention. The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the present application. It should be noted that a technician in the technical field to which the present application belongs may make various modifications or supplements to the described specific embodiments or replace them in a similar manner, but will not deviate from the spirit of the present application or exceed the scope defined in the attached claims. For a person of ordinary skill in the art, multiple variations and improvements may also be made without departing from the concept of the present application. Therefore, the scope of protection of the present application shall be subject to the attached claims.

Claims

1. A method for optimizing intersection operation, characterized in that: include: S1. Set the number of days for data acquisition , obtain the historical parameters of the analysis period and intersection; S2. Obtain the average hourly traffic demand data and the average saturated flow of each direction during the judgment period, calculate the traffic demand and headway of each direction during the judgment period, and calculate the flow rate ratio of each direction during the judgment period; S3. Calculate the flow balance coefficients of the east-west import and the north-south import based on the flow rate ratio, traverse all imports to calculate the flow balance coefficients inside the imports, and compare the difference in the flow rate ratio with the set threshold to determine whether there is an imbalance; S4. Determine the imbalance of east-west imports, north-south imports and internal import flows, and determine the results; S5. Output conclusions based on the analysis results of north-south and east-west imports.

2. The intersection operation optimization evaluation method according to claim 1 is characterized in that: S1 specifically includes obtaining the analysis period The intersection history parameters include intersection channelization information, the number of through lanes at each entrance, and the number of left-turn lanes.

3. The intersection operation optimization evaluation method according to claim 1 is characterized in that: S1 also includes setting different historical data fusion methods: like , then for the previous Days data, before acquisition The traffic demand data of each direction and the real-time headway data of the target intersection in Tianzhong during the judgment period are the same as the current common problems. Day data; like , then directly take the previous The traffic demand data of each direction at the target intersection during the daily data analysis period, and the real-time headway data.

4. The intersection operation optimization evaluation method according to claim 3 is characterized in that: The step S2 includes converting the periodic traffic demand data of each flow direction during the judgment period of each day into hourly traffic demand data, and averaging the data to obtain the first Average hourly traffic demand data for each flow direction during the day .

5. The intersection operation optimization evaluation method according to claim 3 or 4, characterized in that: S2 includes obtaining the saturated flow data of each flow direction during the daily analysis period of the common problems , assuming that the flow direction is Effective saturation flow data , calculate the average saturated flow rate of each flow direction during the judgment period : Calculate saturated headway using saturated flow : If there is no real-time saturation flow data, , In order to configure the configuration parameters of the straight and left-turn headway, the saturated flow rate of each inlet and each flow direction is calculated.

6. The intersection operation optimization evaluation method according to claim 3 is characterized in that: S2 includes calculating the traffic demand and headway time of each flow direction used for the final judgment: in, For traffic demand, that is, intersection import Flow direction transportation needs; is the saturated headway; if the data fusion method is selected , then the average number of days is .

7. The intersection operation optimization evaluation method according to claim 3 or 6, characterized in that: S2 includes calculating the flow rate ratio of each direction in the judgment period according to the traffic demand of each direction and the headway. The flow rate ratio is the ratio of the traffic demand of the direction to the saturated flow rate of the direction, reflecting the traffic load level of each direction: in, is the saturation flow rate, i.e., the inlet Flow direction The saturation flow rate; is the flow rate ratio, i.e., the inlet Flow direction flow rate ratio.

8. The intersection operation optimization evaluation method according to claim 1 is characterized in that: The S3 specifically includes: Calculate the counter-flow balance coefficient of the east-west imports and obtain the import 1, that is, the east import straight flow rate ratio , left turn flow rate ratio , then obtain the straight flow rate ratio of inlet 3, that is, the west inlet , left turn flow rate ratio ; Flow direction There is an opposite flow direction. and , then the east-west import flow The counterflow balance coefficient is: If flow direction j has no opposite flow direction or there is flow direction at the opposite inlet, it is considered as missing data. or , then the east-west import flow The counterflow balance coefficient is 0; Calculate the counterflow balance coefficient of the north-south inlet and obtain the inlet 2, that is, the straight flow rate ratio of the south inlet , left turn flow rate ratio , then obtain the straight flow rate ratio of inlet 4, i.e. the north inlet , left turn flow rate ratio ; Flow direction There is an opposite flow direction. and , then the north-south import flow The counterflow balance coefficient is: Flow direction If there is no opposite flow or there is flow at the opposite inlet, the data is considered missing. or , then the north-south import flow The counterflow balance coefficient is 0, which is the default balance. from Start traversing all imports and calculate the internal flow balance coefficient of the imports The value of the balance coefficient is in the range of [0,1]. The larger the value of the balance coefficient, the greater the difference in the flow rate ratio of the inlet internal flow direction. The calculation formula is as follows: If imported If there is a flow direction, it is judged that the data is missing or there is only one flow direction inside. or , the internal flow balance coefficient is 0, which is the default balance.

9. The intersection operation optimization evaluation method according to claim 1, characterized in that: The S4 specifically includes: recording the opposite inlet with unbalanced opposite flow as a set ; The imports with internal flow imbalance are recorded as a set ; like , that is, there are no imports with unbalanced opposite flows, nor are there imports with unbalanced internal flows, and it is judged as "retaining the existing channelization and optimizing the timing"; like , that is, there are no opposite imports with imbalanced opposite flows, but there are imports with imbalanced internal flows, which are discussed based on the quantity and distribution of imbalanced imports; If the collection There is only one element in , that is, only one import has internal flow imbalance, and the import traffic organization optimization or channelization transformation in set B is judged as "traffic organization optimization"; If the collection There are 2 elements in , that is, there is an internal flow imbalance between the two imports, and the judgment is "retain the existing channelization and optimize the timing"; like , that is, the opposite inlet has flow imbalance, but there is no internal flow imbalance in the inlet. The inlet in set A adopts overlapping phase and is judged as "adopting overlapping phase"; like , that is, the imports with opposite flow imbalance and internal flow imbalance, the set Import traffic organization optimization or channelization transformation in the judgment is "traffic organization optimization"; in, is the east-west import flow balance coefficient, is the north-south import flow balance coefficient, is the inlet internal flow balance coefficient, is the intersection imbalance threshold, is the flow imbalance threshold.

10. The intersection operation optimization evaluation method according to claim 9, characterized in that: S5 specifically includes, for north-south imports and east-west imports: If the judgment results of the two groups of opposite imports are both "keep the existing channelization and optimize the timing", the timing optimization will be started; If at least one pair of opposite imports is judged as "traffic organization optimization" or "increase overlapping phase": the judgment conclusion is output for the imports judged as "traffic organization optimization"; the overlapping phase is recommended and output for the opposite imports judged as "increase overlapping phase".

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