A method and system for allocating traffic flow for carpooling

Abstract

The present invention discloses a method and system for allocating traffic flow for carpooling, including: constructing the original traffic network into an extended network with a three-layer structure by introducing virtual road sections and virtual nodes according to the travel modes available to travelers in the traffic network; calculating the travel costs related to the road sections in the extended network, including travel time costs, fuel costs, inconvenience costs, fees paid by carpooling passengers to carpooling drivers, and income of carpooling drivers, and obtaining the travel costs of the road sections for different travel modes; establishing a carpooling traffic flow allocation model based on the user equilibrium principle, and calculating the traffic flow of different travel modes for each road section in the traffic network. The advantages of the present invention are: solving the travel path selection and travel mode selection problems existing in the carpooling traffic system, obtaining the traffic flow of different travel modes for each road section in the traffic network, saving calculation time and reducing the occupation of computer memory, and solving the problem that passengers cannot avoid transfers.

Description

Technical Field

[0001] The present invention relates to the technical field of urban traffic management, and in particular to a method and system for allocating carpooling traffic flow. Background Art

[0002] With the development of the sharing economy, carpooling, as an emerging mode of travel, has attracted more and more attention due to its potential in alleviating traffic congestion, reducing energy consumption, and its advantage of not increasing the number of motor vehicles. However, in order to understand the impact of carpooling services on the urban transportation system, it is first necessary to study the choice behavior of urban transportation system travelers under carpooling, and then predict the distribution of traffic flow in different transportation modes and road networks. Therefore, the urban transportation network under carpooling involves the problem of travelers' transportation mode selection and travel path selection, that is, the problem of carpooling traffic flow allocation. Specifically, in the urban transportation network under carpooling, all travelers need to choose from three modes of transportation: carpooling drivers, carpooling passengers, and single drivers, and at the same time choose a travel path. Carpooling traffic flow allocation is to predict the spatial distribution of traffic flow of different transportation modes in the transportation network for a given urban transportation network and travel demand distribution.

[0003] In response to the above problems, although some scholars have proposed link-node and path-based methods in the existing studies on carpooling traffic allocation, the former mainly models the link-node based on a single node (starting node or ending node), which may result in carpooling passengers transferring to multiple carpooling vehicles during a trip, which is inconsistent with the actual situation. Although the latter can avoid passengers transferring midway, the modeling method requires enumeration and storage of all or part of the paths between the starting and ending points, which significantly increases the calculation time and occupies a large amount of computer memory.

[0004] Prior art 1

[0005] At present, the segment-node modeling method based on a single node (starting node or ending node) is mainly used to express the relationship between the number of carpooling passengers and carpooling drivers and the average number of passengers on the segment (i, j). [1] In the equation, the expression corresponding to the number constraint relationship between carpooling passengers and carpooling drivers on all road sections is:

[0006]

[0007]

[0008] The average passenger number expression is:

[0009]

[0010] in They correspond to the number of carpooling passengers and the number of carpooling drivers on the road segment (i, j) in the case whose destination is node d. L∪L′ is the set of actual road segments and virtual road segments in the entire extended network, that is, all road segments in the extended network. N′ D is the set of virtual terminal nodes in the entire extended network, Cap is the maximum number of passengers a vehicle can carry, O ij is the average number of passengers per vehicle on the road segment (i, j). The physical meanings of the above constraints are: the number of carpooling passengers with a destination of node d on the road segment (i, j) should be greater than or equal to the number of carpooling drivers with a destination of node d on the road segment; the number of carpooling passengers with a destination of node d on the road segment (i, j) should be less than or equal to the upper limit of the number of passengers provided by the carpooling drivers with a destination of node d on the road segment.

[0011] The existing technology cannot avoid the occurrence of transfer behavior, that is, the carpool driver can pick up or drop off the carpool passengers at any node in the transportation network, so that the carpool passengers need to transfer to multiple carpool vehicles to reach the destination during a trip.

[0012] The above technical shortcomings are now explained by using the Braess network. The network parameter information is shown in the table and the network diagram is shown in Figure 1 As shown in Figure a.

[0013] Table 1 Brays transportation network information

[0014]

[0015] For the convenience of explanation, we now use ABCD to label the shared vehicles in the traffic network, and assume that the path of car A (carrying 3 passengers) is 1-3-2-4, the path of car B (carrying 3 passengers) and car C (carrying 3 passengers) is 1-3-4, and the path of car D (carrying 1 passenger) is 3-4. When the shared driver drives vehicle A to node 3, he lets a passenger get off the car, and vehicle D starting from node 3 can choose to pick up this passenger. In this case, the number of passengers carried by car A becomes 2, the number of passengers carried by cars B and C remains unchanged, still 3, and the number of passengers carried by car D becomes 2, and these two passengers have different origin-destination pairs, which are origin-destination pair 14 and origin-destination pair 34 respectively.

[0016] At this time, the quantity relationship on each road section is as follows:

[0017] Table 2 The number of carpooling drivers and carpooling passengers on each road section and the corresponding relationship between them

[0018]

[0019] According to the data in Table 2, even if a passenger on car A transfers to car D, the quantitative relationship between carpooling passengers and carpooling drivers on each road section still satisfies the constraints established based on a single node, which means that the quantitative relationship constructed based on a single node cannot avoid the occurrence of the above transfer behavior.

[0020] Under the quantitative relationship proposed by the present invention, the quantitative relationship on each road section is as follows:

[0021] Table 3 The number of carpooling drivers and carpooling passengers on each road section and the corresponding relationship between them

[0022]

[0023] According to the data in Table 3, it can be seen that when a passenger on car A transfers to car D, the number of carpooling passengers and carpooling drivers on section 3-4 does not satisfy the quantitative relationship proposed by the present invention, that is, under the constraint of the quantitative relationship of the present invention, car D can only refuse to carry the passenger, that is, the passenger can only continue to take car A and cannot transfer in the middle. Based on the above analysis, it can be known that the present invention can avoid the shortcomings of passenger transfer in the section-node modeling based on a single node.

[0024] Prior art 2

[0025] Based on the path-based modeling method, the relationship between the number of carpooling passengers and carpooling drivers is expressed. [2] In , the expression corresponding to the quantity constraint relationship is:

[0026]

[0027]

[0028] Where C represents the maximum number of passengers in the vehicle in the case, They represent the number of carpooling passengers and the number of carpooling drivers on the pth path between the origin-destination pair (OD pair) ω, respectively. The physical meanings of the above constraints are: the number of carpooling passengers on the pth path between the origin-destination pair ω should be greater than or equal to the number of carpooling drivers on the path; the number of carpooling passengers on the pth path between the origin-destination pair ω should be less than or equal to the upper limit of the number of passengers provided by the carpooling drivers on the path.

[0029] Since the second existing technology is based on path modeling, path enumeration is required in the case analysis. When the scale of the traffic network is large, this method has a large workload, a high error rate and occupies a large amount of computer memory. In other words, the applicability of this technology decreases as the scale of the case traffic network increases.

[0030] References

[0031] [1] Chen X, Di X. Ridesharing user equilibrium with nodal matching cost and its implications for congestion tolling and platform pricing[J]. Transportation Research Part C: Emerging Technologies, 2021, 129: 103233;

[0032] [2] Di X, Liu H X, Ban X, et al. Ridesharing user equilibrium and its implications for high-occupancy toll lane pricing[J]. Transportation Research Record, 2017, 2667(1): 39 - 50;

[0033] [3] Di X, Ma R, Liu H X, et al. A link-node reformulation of ridesharing user equilibrium with network design[J]. Transportation Research Part B: Methodological, 2018, 112: 230 - 255;

[0034] [4] Larsson T, Patriksson M. Side constrained traffic equilibrium models—analysis, computation and applications[J]. Transportation Research Part B: Methodological, 1999, 33(4): 233 - 264;

[0035] [5]Li Y, Liu Y, Xie JA path-based equilibrium model for ridesharingmatching[J]. Transportation Research Part B: Methodological, 2020, 138: 373-405. Summary of the invention

[0036] In view of the defects of the prior art, the present invention provides a method and system for allocating traffic flow in carpooling. The problem of travel route selection in the urban transportation system and the problem of transportation mode selection of travelers under carpooling can be solved, and the distribution of traffic flow of different transportation modes in the road network can be obtained. In addition, the present invention strictly constrains the quantitative relationship between carpooling drivers and carpooling passengers by adopting the link-node modeling based on the origin and destination pairs (OD-based). It can not only eliminate the disadvantage that the quantitative relationship in the link-node modeling method based on a single node (starting node or ending node) cannot avoid passenger transfers, but also avoid the disadvantage that path-based modeling requires path enumeration.

[0037] In order to achieve the above invention object, the technical solution adopted by the present invention is as follows:

[0038] A method for allocating carpooling traffic flow comprises the following steps:

[0039] Step 1: Expand the network construction;

[0040] Firstly, the original traffic network is replicated into three-layer networks according to the travel modes available to travelers in the traffic network, namely: single-driver network layer, carpool driver network layer and carpool passenger network layer.

[0041] At the same time, symbols are used to represent the travel modes of traffic travelers and the collection of nodes and road sections in each layer of the network: a single driver is represented by v, and the collection of actual nodes in the single driver network is recorded as N (v) , the road segment set is The carpool driver is denoted by d, and the set of actual nodes in the carpool driver network is denoted by N (d) , the road segment set is The carpooling passenger is represented by p, and the actual nodes in the carpooling passenger network layer are the set N (p) , the road segment set is

[0042] Secondly, the three-layer network is connected by introducing virtual segments, virtual start nodes and virtual end nodes. The virtual segment set is defined as A′, the virtual start node set is N′, and the virtual end node set is N′. D The construction of the extended network is demonstrated using a single-starting and single-destination transportation network.

[0043] Step 2: Calculate road capacity;

[0044] The traffic capacity of each road section is calculated as follows:

[0045]

[0046] Y ij represents the total number of lanes in the road section (i, j), and θ is the capacity of a single lane.

[0047] Step 3: Calculate travel time, travel time cost, fuel cost and inconvenience cost, calculate the cost that carpooling passengers need to pay to carpooling drivers, calculate the income of carpooling drivers and calculate the travel costs of different travelers;

[0048] The meaning of inconvenience cost: Unlike travelers who choose to drive alone or take a special car, passengers and drivers who choose to share a vehicle need to endure the inconvenience of sharing a vehicle with others. The inconvenience cost is related to the average number of passengers in each shared vehicle. In the same vehicle, the more passengers there are, the greater the inconvenience cost the passengers and drivers need to pay. When the number of passengers reaches the maximum passenger capacity of the vehicle, the inconvenience cost reaches its maximum.

[0049] Step 4: Establish constraints for link-node modeling based on origin-destination pairs, including: quantity relationship constraints, user equilibrium constraints, flow and demand constraints

[0050] User equilibrium constraint: In the user equilibrium (UE) state, if a segment (i, j) is on the shortest path from the start node r to the end node s and carries traffic, then its segment travel cost should be equal to the minimum cost from node i to node j on the OD pair rs;

[0051] Step 5: Use GAMS to program the contents of the above steps and solve them using the PATH solver in GAMS.

[0052] Furthermore, the specific sub-steps of step 3 are as follows:

[0053] Step 31: The travel time is calculated as follows:

[0054]

[0055] Among them, t ijis the travel time of road segment (i,j), represents the free flow travel time on road segment (i, j); represents the traffic volume of road section (i, j); c ij represents the capacity of road section (i, j); α, β are non-negative parameters of the Bureau of Highway Research (BPR) function.

[0056] The vehicles on the road section can be divided into two categories: carpooling vehicles and single-driver vehicles. The number of carpooling vehicles is equal to the flow of carpooling drivers on the road section (i, j); the number of single-driver vehicles is equal to the flow of single-driver drivers on the road section (i, j). Therefore, the traffic flow can be expressed as the flow of carpooling drivers between each OD pair rs. and traffic of solo drivers sum express.

[0057] Step 32: Convert travel time into travel time cost by introducing time value η

[0058]

[0059] in, represents the travel time cost of road section (i, j), η is the time value, that is, the amount of money corresponding to unit time, t ij is the travel time of road segment (i, j).

[0060] Step 33: The fuel cost is calculated as follows:

[0061]

[0062] in, represents the fuel cost of road section (i,j), τ f is the fuel cost per unit distance during driving, l ij is the length of the road segment (i, j).

[0063] Step 34: The inconvenience cost is calculated as follows:

[0064]

[0065]

[0066]

[0067]

[0068] in, represents the inconvenience cost of carpooling on road section (i, j); τ uIndicates the inconvenience fee when sharing a ride with a stranger. represents the average number of passengers per vehicle on the road section (i, j) between OD and RS, represents the number of carpooling drivers on the road section (i, j) between OD pair rs, Represents the number of passengers sharing a ride on the road section (i, j) between the OD pair rs.

[0069] Step 35: Calculate the fee τ that the carpooling passenger needs to pay to the carpooling driver ij , the cost is related to the length l of the road segment (i,j) ij There is a linear positive correlation, the linear relationship coefficient is ρ≥0, and the calculation formula is as follows:

[0070]

[0071] Among them, τ ij The fee that each carpool passenger needs to pay to the carpool driver, ij is the length of the road section (i, j), and ρ is the fee per unit length.

[0072] Step 36: Calculate rideshare driver earnings

[0073]

[0074] in, represents the income of each carpool driver, τ ij The fee that each carpool passenger needs to pay to the carpool driver, It represents the average number of passengers per vehicle on the road segment (i, j) between the OD pair RS.

[0075] Step 37: Calculate the travel costs of different travelers:

[0076] The travel cost of a solo driver consists of two parts: travel time cost and fuel cost; the travel cost of a carpool driver consists of four parts: travel time cost, fuel cost, inconvenience cost and driver income; the travel cost of a carpool passenger consists of three parts: travel time cost, inconvenience cost and the fee that the passenger needs to pay to the carpool driver.

[0077]

[0078] in, represents the travel cost of a single driver, represents the travel cost of the carpool driver, represents the travel cost of the carpooling passengers, Indicates the travel time cost, Indicates fuel cost, Inconvenience cost, represents the income of the ride-sharing driver, τ ij It means that carpool passengers need to pay the carpool driver.

[0079] Further, in step 34, when When To avoid this problem, the average number of passengers can be regarded as the optimal solution of the following quadratic programming:

[0080]

[0081] Among them, O is the independent variable, which represents the number of passengers per vehicle. represents the number of carpooling drivers on the road section (i, j) between the OD pair rs, Represents the number of passengers sharing a ride on the road section (i, j) between the OD pair rs.

[0082] The complementary conditions corresponding to the quadratic programming are as follows, and the average number of passengers can be solved using the following complementary formula:

[0083]

[0084]

[0085]

[0086] in, represents the average number of passengers on the OD-RS link (i, j), represents the number of carpooling drivers on the road section (i, j) between the OD pair rs, represents the number of passengers sharing a ride on the segment (i, j) between the OD pair rs; For and Constraints The corresponding multiplier, For and Constraints The corresponding multiplier, Cap, is the maximum number of passengers per vehicle.

[0087] Furthermore, the sub-steps of step 4 are as follows:

[0088] Step 41: Quantity relationship constraint condition: limits the quantity relationship between carpooling passengers and carpooling drivers with the same origin and destination pair on the road segment (i, j).

[0089]

[0090]

[0091] in, represents the number of carpooling drivers on the road section (i, j) between the OD pair rs, represents the number of passengers sharing a ride on the segment (i, j) between the OD pair rs; For The multiplier corresponding to the quantitative relationship is For The corresponding multiplier; Cap is the maximum number of passengers per vehicle.

[0092] The generalized road segment travel costs of various types of travelers are as follows:

[0093]

[0094] in, represents the generalized travel cost of a single driver, represents the generalized travel cost of the carpooling driver, Express the generalized travel costs of carpool passengers; represents the travel cost of a single driver, represents the travel cost of the carpool driver, travel costs for carpool passengers; For The multiplier corresponding to the quantitative relationship is For The corresponding multiplier, Cap, is the maximum number of passengers per vehicle.

[0095] Step 42: UE equilibrium constraint: In the user equilibrium state, if the segment (i, j) is on the shortest path from node r to the end node s and carries traffic, then its segment travel cost should be equal to the minimum cost from node i to node j on OD pair rs, as follows:

[0096]

[0097]

[0098]

[0099] in, They represent the number of single drivers, carpooling drivers and carpooling passengers on the road segment (i, j) between the OD pair rs respectively; They represent the generalized travel costs of the single driver, the carpool driver and the carpool passenger on the road segment (i, j) between the OD pair rs respectively; represents the node potential of node j between OD and RS on the single driver network layer in the extended network, represents the node potential of node i between OD and RS in the extended network, represents the minimum travel cost between node j and node i between OD pair rs on the network layer of the single driver in the extended network; represents the node potential of node j between OD pairs rs on the carpooling driver network layer in the extended network, represents the node potential of node i between OD and RS in the carpooling driver network layer in the extended network, represents the minimum travel cost between node j and node i between OD pair rs on the carpool driver network layer in the extended network; represents the node potential of node j between OD pairs rs on the shared passenger network layer in the extended network, represents the node potential of node i between OD pairs rs on the shared passenger network layer in the extended network, It represents the minimum travel cost between node j and node i between OD pair rs on the shared passenger network layer in the extended network.

[0100] Step 43: The travel cost of the virtual road segment is zero, and the formula is as follows:

[0101] The UE balancing constraint expression on the virtual starting section is:

[0102]

[0103]

[0104]

[0105] in, represents the node potential of the virtual starting node between OD and RS in the extended network, represents the number of independent drivers on the virtual starting section connecting the virtual starting node between the OD pair RS and the independent driver network layer starting node in the extended network, represents the node potential of the starting node on the network layer of the individual driver between the OD pair RS in the extended network, represents the minimum travel cost between the virtual starting node between OD pairs in the extended network and the starting node on the single driver network layer; represents the number of carpool drivers on the virtual starting section connecting the virtual starting node between the OD pair RS in the extended network and the starting node of the carpool driver network layer, represents the node potential of the starting node on the network layer of the shared driver between OD pairs RS in the extended network, represents the minimum travel cost between the virtual starting node between OD pairs in the extended network and the starting node on the carpooling driver network layer; represents the number of carpooling passengers on the virtual starting section connecting the virtual starting node between the OD pair RS in the extended network and the starting node of the carpooling passenger network layer, represents the node potential of the starting node on the passenger network layer between OD pairs RS in the extended network, It represents the minimum travel cost between the virtual starting node between OD pairs in the extended network and the starting node on the shared passenger network layer.

[0106] The UE balancing constraint expression on the virtual termination section is:

[0107]

[0108]

[0109]

[0110] in, represents the node potential of the virtual termination node between OD and RS in the extended network, represents the number of independent drivers on the network layer termination node and virtual termination node and the connected virtual termination road section between OD pairs RS in the extended network, represents the node potential of the termination node on the network layer of the individual driver between the OD pair RS in the extended network, represents the minimum travel cost between the end node and the virtual end node on the network layer of the individual driver between the OD pairs in the extended network; represents the number of carpool drivers on the virtual termination section connecting the network layer termination node and the virtual termination node between OD pairs RS in the extended network, represents the node potential of the termination node on the network layer of the shared driver between OD pairs RS in the extended network, represents the minimum travel cost between the end node and the virtual end node on the network layer of the carpooling driver between OD pairs in the extended network; represents the number of carpooling passengers on the virtual termination section connecting the network layer termination node and the virtual termination node between OD pairs RS in the extended network, represents the node potential of the terminal node on the passenger network layer between OD pairs RS in the extended network, It represents the minimum travel cost between the end node and the virtual end node on the network layer of the shared passengers between OD pairs in the extended network.

[0111] Step 44: Flow and demand constraints: Satisfy the flow conservation constraint, that is, the difference between the flow inflow and outflow from any intermediate node should be 0. The virtual start node and the virtual end node need to satisfy the demand conservation constraint. The set of all road segments in the entire extended network is recorded as The travel demand between OD and RS is recorded as

[0112]

[0113]

[0114]

[0115] Among them, m represents the set of three types of travel modes: single drivers, carpool drivers and carpool passengers. represents the number of m-th travel modes on the road segment (i, j) between OD pair RS, represents the number of m-th travel modes on the road segment (k,i) between the OD pair RS, represents the sum of the number of users of the mth type flowing out from node i between OD pair rs, represents the sum of the number of users of the mth type flowing in from node i between OD pair rs; represents the total traffic demand of OD on the virtual starting node r between rs, They represent the number of single drivers, carpool drivers and carpool passengers on the road segment (i, j) between the OD pair rs respectively; represents the total traffic volume flowing out of the virtual starting node r between OD pairs rs; It represents the total traffic volume flowing into the virtual termination node s between OD pair rs.

[0116] The present invention also provides a carpooling traffic flow allocation system, which can be used to implement the above-mentioned carpooling traffic flow allocation method, specifically, including: an expansion network module, a road capacity calculation module, a cost calculation module, a constraint module and a solution module;

[0117] Expanded network module: The original traffic network is replicated into three layers of networks according to the travel modes available to travelers in the traffic network, namely: a single driver network layer, a carpool driver network layer, and a carpool passenger network layer;

[0118] Symbols are used to represent the travel modes of traffic travelers and the collection of nodes and road segments in each layer of the network:

[0119] The three-layer network is connected by introducing virtual road segments, virtual start nodes and virtual end nodes, and symbols are used to represent the set of virtual road segments, the set of virtual start nodes and the set of virtual end nodes.

[0120] Road capacity calculation module; calculates road capacity;

[0121] Cost calculation module: used to calculate travel time, travel time cost, fuel cost, inconvenience cost, cost that carpooling passengers need to pay to carpooling drivers, income of carpooling drivers and travel costs of different travelers;

[0122] Constraint module: establishes OD-based constraint relationships, including: quantity relationship constraints, UE balance constraints, and traffic and demand constraints;

[0123] Solution module: Use the PATH solver in GAMS to solve.

[0124] The present invention also discloses a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the above-mentioned method for allocating shared travel traffic flow is implemented.

[0125] Compared with the prior art, the advantages of the present invention are:

[0126] The present invention can solve the travel path selection problem and the traveler transportation mode selection problem existing in the urban transportation system under the participation of carpooling, and obtain the number of different types of travelers in the transportation network. In addition, the present invention not only avoids the need to enumerate and store all or part of the paths between the starting and ending points in path modeling, saving calculation time and reducing the occupation of computer memory; but also eliminates the drawback that the quantitative relationship in the link-node modeling method based on a single node (starting node or ending node) cannot avoid passenger transfers by constraining the quantitative relationship between carpooling drivers and carpooling passengers, so that the results are more in line with the actual situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0127] Figure 1 It is the schematic diagram of the Brays network (Figure a) and the traffic distribution result diagram (Figure b);

[0128] Figure 2 It is the original traffic network diagram and the expanded traffic network diagram;

[0129] Figure 3 is a schematic diagram of an expanded transportation network according to an embodiment of the present invention;

[0130] Figure 4 It is a schematic diagram of the Nguyen-Dupuis network of an embodiment of the present invention. DETAILED DESCRIPTION

[0131] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples.

[0132] A method for allocating carpooling traffic flow comprises the following steps:

[0133] Step 1: Expand the network construction;

[0134] First, the original traffic network is replicated into three layers according to the travel modes that travelers can choose in the traffic network, namely: single driver network layer, carpool driver network layer and carpool passenger network layer. At the same time, the travel modes of traffic travelers and the collection of nodes and sections in each layer of the network are represented by symbols: single drivers are represented by v, and the collection of actual nodes in the single driver network is recorded as N (v) , the road segment set is The carpool driver is denoted by d, and the set of actual nodes in the carpool driver network is denoted by N (d) , the road segment set is The carpooling passenger is represented by p, and the actual nodes in the carpooling passenger network layer are the set N (p) , the road segment set is Secondly, the three-layer network is connected by introducing virtual segments, virtual start nodes and virtual end nodes. The set of virtual segments is A′, the set of virtual start nodes is N′, and the set of virtual end nodes is N′. D The construction of the extended network is demonstrated using a single-start and single-destination transportation network. Figure 2 .

[0135] Step 2: Calculate road capacity;

[0136] The traffic capacity of each road section is the total number of lanes Y ij The product of the single lane capacity θ

[0137]

[0138] Y ij represents the total number of lanes in the road section (i, j), and θ is the capacity of a single lane.

[0139] Step 3: Cost calculation, basic cost calculation, travel time cost calculation;

[0140] Travel time: ij is the travel time of road segment (i, j), and is represented by the well-known Bureau of Highway Research (BPR) travel time function.

[0141]

[0142] Among them, t ij represents the travel time on road segment (i, j), represents the free flow travel time on road segment (i, j); x ij represents the traffic volume of road section (i, j); c ij represents the traffic capacity of road section (i, j); α, β are non-negative parameters of the BPR function.

[0143] The vehicles on the road segment can be divided into two categories: carpooling vehicles and single-driver vehicles. The number of carpooling vehicles is equal to the flow of all carpooling drivers on the road segment (i, j). The number of single-driver vehicles is equal to the total number of single-driver drivers on the road segment (i, j) That is, traffic volume x ij The sum of the traffic of carpool drivers and the traffic of solo drivers can be used Because the present invention adopts the segment-node modeling method based on OD pairs, the flow of the three types of travelers on the segment (i, j) can be represented by the sum of the corresponding traveler flows between each OD pair rs passing through the segment (i, j), and the calculation formula is as follows:

[0144]

[0145] in, They represent the flow numbers of all single drivers, all carpool drivers, and all carpool passengers on the road section (i, j) respectively; They represent the number of single drivers, carpooling drivers and carpooling passengers on the road segment (i, j) between the OD pair rs.

[0146] In summary, the travel time calculation formula can be replaced by the following formula:

[0147]

[0148] Among them, t ij is the travel time of road segment (i,j), represents the free flow travel time on road segment (i, j);

[0149] represents the traffic volume of road section (i, j); c ij represents the traffic capacity of road section (i, j); α, β are non-negative parameters of the BPR function.

[0150] By introducing the value of time η (VOT: value of time, the amount of money corresponding to a unit of time), travel time is converted into travel time costs

[0151]

[0152] in, represents the travel time cost of road section (i, j), η is the time value, that is, the amount of money corresponding to unit time, t ij is the travel time of road segment (i, j).

[0153] Fuel costs:

[0154]

[0155] in, represents the fuel cost of road section (i,j), τ f is the fuel cost per unit distance during driving, l ij is the length of the road segment (i, j).

[0156] Calculation of additional costs for carpooling

[0157] Unlike those who choose to drive alone or take a private car, passengers and drivers who choose to share a ride need to endure the inconvenience of sharing a vehicle with others, such as the time it takes for passengers to get on and off the vehicle, and the discomfort caused by sharing the same space with strangers. According to actual experience, the inconvenience cost is related to the average number of passengers in each shared vehicle. In other words, the more passengers there are in the same vehicle, the more discomfort each passenger and driver feels. That is, the greater the inconvenience cost that passengers and drivers need to pay, the greater the inconvenience cost will be. When the number of passengers reaches the maximum passenger capacity of the vehicle, the inconvenience cost reaches its maximum.

[0158] Inconvenience cost:

[0159]

[0160]

[0161]

[0162]

[0163] in, represents the inconvenience cost of carpooling on road section (i, j); τ u Indicates the inconvenience fee when sharing a ride with a stranger. represents the average number of passengers on the road section (i, j) from the starting point r to the end point s, represents the number of passengers sharing a ride on the road section (i, j) from the starting point r to the end point s, Represents the number of carpooling drivers on the road section (i, j) from the starting point r to the end point s.

[0164] when (The number of drivers in the carpooling trip is 0), it will result in To avoid this problem, by solving the linear complementarity problem of average passenger occupancy rate, it can be regarded as the optimal solution of the following quadratic programming (Di Xuan [3] )

[0165]

[0166] Among them, O is the independent variable, which represents the number of passengers per vehicle. represents the number of carpooling drivers on the road section (i, j) between the OD pair rs, Represents the number of passengers sharing a ride on the road section (i, j) between the OD pair rs.

[0167] The complementary conditions corresponding to the quadratic programming are as follows, and the average number of passengers can be solved using the following complementary formula:

[0168]

[0169]

[0170]

[0171] in, represents the average number of passengers on the OD-RS link (i, j), represents the number of carpooling drivers on the road section (i, j) between the OD pair rs, represents the number of passengers sharing a ride on the segment (i, j) between the OD pair rs; For and Constraints The corresponding multiplier, For and Constraints The corresponding multiplier, Cap, is the maximum number of passengers per vehicle.

[0172] The fee that carpool passengers need to pay to carpool drivers τ ij : The carpooling passengers need to pay the carpooling driver the fare τ during the entire carpooling trip ij , the cost is related to the length l of the road segment (i, j) ij There is a linear positive correlation, and the linear relationship coefficient is ρ≥0.

[0173]

[0174] Among them, τ ij The fee that each carpool passenger needs to pay to the carpool driver, ij is the length of the road section (i, j), and ρ is the fee per unit length.

[0175] Rideshare driver income

[0176]

[0177] in, represents the income of each carpool driver, τ ij The fee that each carpool passenger needs to pay to the carpool driver, It represents the average number of passengers per vehicle on the road segment (i, j) between the OD pair RS.

[0178] According to the above two sections, the travel costs of different travelers can be obtained as follows:

[0179]

[0180] in, represents the travel cost of a single driver, represents the travel cost of the carpool driver, represents the travel cost of the shared passengers, Indicates the travel time cost, Indicates fuel cost, Inconvenience cost, represents the income of the ride-sharing driver, τ ij It means that carpool passengers need to pay the carpool driver.

[0181] Step 4: OD-based constraint relationships

[0182] Quantitative relationship: It defines the quantitative relationship between the carpooling passengers and carpooling drivers’ homes with the same origin and destination pair on the road section (i, j).

[0183]

[0184]

[0185] in, represents the number of carpooling drivers on the road section (i, j) between the OD pair rs, It represents the number of passengers sharing a ride on the road section (i, j) between the OD pair rs, and Cap is the maximum number of passengers per vehicle.

[0186] The carpooling user equilibrium satisfies Wardrop's first principle in terms of generalized travel costs, rather than actual travel costs (Larsson and Patriksson, 1999 [4] ). Therefore, the generalized road segment travel costs of various types of travelers are as follows:

[0187]

[0188] in, represents the generalized travel cost of a single driver, represents the generalized travel cost of the carpooling driver, Express the generalized travel costs of carpool passengers; represents the travel cost of a single driver, represents the travel cost of the carpool driver, travel costs for carpool passengers; For The corresponding multiplier, For The corresponding multiplier, Cap, is the maximum number of passengers per vehicle.

[0189] User equilibrium constraint: In the user equilibrium (UE) state, if a segment (i, j) is on the shortest path from node r to the end node s and carries traffic, then its segment travel cost should be equal to the minimum cost from node i to node j on the OD pair rs.

[0190]

[0191]

[0192]

[0193] in, They represent the number of single drivers, carpooling drivers and carpooling passengers on the road segment (i, j) between the OD pair rs respectively; They represent the generalized travel costs of the single driver, the carpool driver and the carpool passenger on the road segment (i, j) between the OD pair rs respectively; represents the node potential of node j between OD and RS on the single driver network layer in the extended network, represents the node potential of node i between OD and RS in the extended network, represents the minimum travel cost between node j and node i between OD pair rs on the network layer of the single driver in the extended network; represents the node potential of node j between OD pairs rs on the carpooling driver network layer in the extended network, represents the node potential of node i between OD and RS in the carpooling driver network layer in the extended network, represents the minimum travel cost between node j and node i between OD pair rs on the carpool driver network layer in the extended network; represents the node potential of node j between OD pairs rs on the shared passenger network layer in the extended network, represents the node potential of node i between OD pairs rs on the shared passenger network layer in the extended network, It represents the minimum travel cost between node j and node i between OD pair rs on the shared passenger network layer in the extended network.

[0194] The virtual road segment is used to connect the three-layer extended network. It does not carry any information about travel, so the travel cost of the virtual road segment is zero.

[0195] The UE balancing constraint expression on the virtual starting section is:

[0196]

[0197]

[0198]

[0199] in, represents the node potential of the virtual starting node between OD and RS in the extended network, represents the number of independent drivers on the virtual starting section connecting the virtual starting node between the OD pair RS and the independent driver network layer starting node in the extended network, represents the node potential of the starting node on the network layer of the individual driver between the OD pair RS in the extended network, represents the minimum travel cost between the virtual starting node between OD pairs in the extended network and the starting node on the single driver network layer; represents the number of carpool drivers on the virtual starting section connecting the virtual starting node between the OD pair RS in the extended network and the starting node of the carpool driver network layer, represents the node potential of the starting node on the network layer of the shared driver between OD pairs RS in the extended network, represents the minimum travel cost between the virtual starting node between OD pairs in the extended network and the starting node on the carpooling driver network layer; represents the number of carpooling passengers on the virtual starting section connecting the virtual starting node between the OD pair RS in the extended network and the starting node of the carpooling passenger network layer,

[0200] represents the node potential of the starting node on the passenger network layer between OD pairs RS in the extended network, It represents the minimum travel cost between the virtual starting node between OD pairs in the extended network and the starting node on the shared passenger network layer.

[0201] The UE balancing constraint expression on the virtual termination section is:

[0202]

[0203]

[0204]

[0205] in, represents the node potential of the virtual termination node between OD and RS in the extended network, represents the number of independent drivers on the network layer termination node and virtual termination node and the connected virtual termination road section between OD pairs RS in the extended network, represents the node potential of the termination node on the network layer of the individual driver between the OD pair RS in the extended network, represents the minimum travel cost between the end node and the virtual end node on the network layer of the individual driver between the OD pairs in the extended network; represents the number of carpool drivers on the virtual termination section connecting the network layer termination node and the virtual termination node between the OD pair RS in the extended network, represents the node potential of the terminal node on the network layer of the shared driver between OD pairs RS in the extended network, represents the minimum travel cost between the end node and the virtual end node on the network layer of the carpooling driver between OD pairs in the extended network; represents the number of carpooling passengers on the virtual termination section connecting the network layer termination node and the virtual termination node between OD pairs RS in the extended network, represents the node potential of the terminal node on the passenger network layer between OD pairs RS in the extended network, It represents the minimum travel cost between the end node and the virtual end node on the network layer of the shared passengers between OD pairs in the extended network.

[0206] Traffic and demand constraints: For the entire extended network, all nodes except the virtual start node and the virtual end node are intermediate nodes and need to satisfy the traffic conservation constraint (that is, the difference between the flow inflow and the flow outflow from any intermediate node should be 0). The virtual start node and the virtual end node need to satisfy the demand conservation constraint. The set of all road segments in the entire extended network is recorded as The travel demand between OD and RS is recorded as

[0207]

[0208]

[0209]

[0210] Among them, m represents the set of three types of travel modes: single drivers, carpool drivers and carpool passengers. represents the number of m-th travel modes on the road segment (i, j) between OD pair RS, represents the number of m-th travel modes on the road segment (k, i) between the OD pair rs; represents the total traffic demand of OD on the virtual starting node r between rs, They represent the number of single drivers, carpool drivers and carpool passengers on the road segment (i, j) between the OD pair rs respectively; represents the total traffic volume flowing out of the virtual starting node r between OD pairs rs; It represents the total traffic volume flowing into the virtual termination node s between OD pair rs.

[0211] Step 5: Use GAMS (version win64 25.1.3) to program the contents involved in the above steps and use the PATH solver in GAMS to solve them.

[0212] This embodiment adopts the Nguyen-Dupuis network (such as Figure 3 The network is shown in Figure 4), which contains 13 nodes (starting nodes 1 and 4, ending nodes 2 and 3), 19 road segments and 4 OD pairs (1-2, 1-3, 4-2 and 4-3). The information parameters of the network are shown in Table 4. The corresponding extended network has 4 OD pairs, 61 road segments and 43 nodes.

[0213] The traffic distribution method proposed in the patent of this invention is used to distribute the traffic in the traffic network. The relevant parameters in the model are set as follows: θ = 2000Veh / h; α = 0.15; β = 4; η = 1￥ / min; τ f =0.68￥ / km; τ=3￥ / person;

[0214] ρ = 0.476 ￥ / km; Cap = 3 people / vehicle; travel demand is shown in Table 5;

[0215] According to the above steps, GAMS programming is performed to obtain the flow distribution results shown in Table 6. After inspection, the flow distribution results meet the quantity constraints of carpooling drivers and carpooling passengers.

[0216] Table 4: Segment parameters of the Nguyen-Dupuis network

[0217]

[0218]

[0219] Table 5: Travel Demand

[0220] OD Travel demand (vehicles) 1-2 6600 1-3 4940 4-2 4120 4-3 4940

[0221] Table 6: Flow distribution results

[0222]

[0223]

[0224] In another embodiment of the present invention, a system for allocating carpooling traffic flow is provided. The system can be used to implement the above-mentioned carpooling traffic flow allocation method, and specifically includes: an expansion network module, a road capacity calculation module, a cost calculation module, a constraint module and a solution module;

[0225] Expanded network module: The original traffic network is replicated into three layers of networks according to the travel modes available to travelers in the traffic network, namely: a single driver network layer, a carpool driver network layer, and a carpool passenger network layer;

[0226] Symbols are used to represent the travel modes of traffic travelers and the collection of nodes and road segments in each layer of the network:

[0227] The three-layer network is connected by introducing virtual road segments, virtual start nodes and virtual end nodes, and symbols are used to represent the set of virtual road segments, the set of virtual start nodes and the set of virtual end nodes.

[0228] Road capacity calculation module; calculates road capacity;

[0229] Cost calculation module: used to calculate travel time, travel time cost, fuel cost, inconvenience cost, cost that carpooling passengers need to pay to carpooling drivers, income of carpooling drivers and travel costs of different travelers;

[0230] Constraint module: establish OD-based constraint relationships, including: quantity relationship constraints, user balance constraints, flow and demand constraints;

[0231] Solution module: Use the PATH solver in GAMS to solve.

[0232] In another embodiment of the present invention, the present invention further provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a terminal device for storing programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and the extended storage medium supported by the terminal device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory, or a non-volatile memory (non-volatile memory), such as at least one disk storage.

[0233] The processor may load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the method for allocating carpooling traffic flow in the above embodiment; the processor may load and execute the following steps:

[0234] Step 1: Expand the network construction;

[0235] Firstly, the original traffic network is replicated into three-layer networks according to the travel modes available to travelers in the traffic network, namely: single-driver network layer, carpool driver network layer and carpool passenger network layer.

[0236] At the same time, symbols are used to represent the travel modes of traffic travelers and the collection of nodes and road sections in each layer of the network: a single driver is represented by v, and the collection of actual nodes in the single driver network is recorded as N (v) , the road segment set is The carpool driver is denoted by d, and the set of actual nodes in the carpool driver network is denoted by N (d) , the road segment set is The carpooling passenger is represented by p, and the actual nodes in the carpooling passenger network layer are the set N (p) , the road segment set is

[0237] Secondly, the three-layer network is connected by introducing virtual segments, virtual start nodes and virtual end nodes. The set of virtual segments is A′, and the set of virtual start nodes is N′ R , the set of virtual termination nodes is N′ D The construction of the extended network is demonstrated using a single-starting and single-destination transportation network.

[0238] Step 2: Calculate road capacity;

[0239] The traffic capacity of each road section is the corresponding number of lanes Y ij The product of the single lane capacity θ is as follows:

[0240]

[0241] Y ij represents the total number of lanes in the road section (i, j), and θ is the capacity of a single lane.

[0242] Step 3: Calculate travel time, travel time cost, fuel cost and inconvenience cost, calculate the cost that carpool passengers need to pay to carpool drivers, calculate the income of carpool drivers and calculate the travel costs of different travelers;

[0243] The meaning of inconvenience cost: Unlike travelers who choose to drive alone or take a special car, passengers and drivers who choose to share a vehicle need to endure the inconvenience of sharing a vehicle with others. The inconvenience cost is related to the average number of passengers in each shared vehicle. In the same vehicle, the more passengers there are, the greater the inconvenience cost the passengers and drivers need to pay. When the number of passengers reaches the maximum passenger capacity of the vehicle, the inconvenience cost reaches its maximum.

[0244] Step 4: Establish OD-based constraints, including: quantity constraints, UE balance constraints, flow and demand constraints

[0245] User equilibrium constraint: In the user equilibrium (UE) state, if a segment (i, j) is on the shortest path from node r to the terminal node s and carries traffic, then its segment travel cost should be equal to the minimum cost from node i to node j on OD pair rs;

[0246] Step 5: Use GAMS to program the contents of the above steps and solve them using the PATH solver in GAMS.

[0247] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0248] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0249] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0250] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0251] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the implementation methods of the present invention, and should be understood that the protection scope of the present invention is not limited to such special statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A method for allocating carpooling traffic flow, characterized in that: The following steps are involved: Step 1: Expand the network construction; Firstly, the original traffic network is replicated into three layers according to the travel modes of the travelers in the traffic network, namely: single driver network layer, carpool driver network layer and carpool passenger network layer; At the same time, symbols are used to represent the travel modes of traffic travelers and the collection of nodes and road sections in each layer of the network: the single driver is represented by v, and the collection of actual nodes in the single driver network layer is recorded as N (v) , the road segment set is The carpool driver is denoted by d, and the set of actual nodes in the carpool driver network layer is denoted by N (d) , the road segment set is The carpooling passenger is represented by p, and the actual nodes in the carpooling passenger network layer are the set N (p) , the road segment set is Secondly, the three-layer network is connected by introducing virtual segments, virtual start nodes and virtual end nodes; and the set of virtual segments is denoted as A′, and the set of virtual start nodes is denoted as N′ R , the set of virtual termination nodes is N′ D ; The construction of the extended network is demonstrated using a single-starting and single-destination transportation network; Step 2: Calculate road capacity; The traffic capacity of each road section is calculated as follows: Y ij represents the total number of lanes in the road section (i, j), and θ is the capacity of a single lane; Step 3: Calculate travel time, travel time cost, fuel cost and inconvenience cost, calculate the cost that carpooling passengers need to pay to carpooling drivers, calculate the income of carpooling drivers and calculate the travel costs of different travelers; Meaning of inconvenience cost: Different from those who choose to drive alone or take a private car, passengers and drivers who choose to share a vehicle need to bear the inconvenience of sharing a vehicle with others. The inconvenience cost is related to the average number of passengers in each shared vehicle. In the same vehicle, the more passengers there are, the greater the inconvenience cost that passengers and drivers need to pay. When the number of passengers reaches the maximum passenger capacity of the vehicle, the inconvenience cost reaches the maximum. Step 4: Establish constraints for link-node modeling based on origin-destination pairs, including: quantity relationship constraints, UE balance constraints, flow and demand constraints UE equilibrium constraint: In the user equilibrium UE state, if the road segment (i, j) is on the shortest path from the starting node r to the ending node s and carries traffic, then its road segment travel cost should be equal to the minimum cost from node i to node j on the OD pair rs; Step 5: Use GAMS to program the contents of the above steps and solve them using the PATH solver in GAMS.

2. A method for allocating carpooling traffic flow according to claim 1, characterized in that: The specific sub-steps of step 3 are as follows: Step 31: The travel time is calculated as follows: Among them, t ij is the travel time of road segment (i,j), represents the free flow travel time on road segment (i, j); represents the traffic volume of road section (i, j); c ij represents the capacity of the road section (i, j); α, β are non-negative parameters of the BPR function of the US Highway Administration; The vehicles on the road section can be divided into two categories: carpooling vehicles and single-driver vehicles; the number of carpooling vehicles is equal to the flow of carpooling drivers on the road section (i, j); the number of single-driver vehicles is equal to the flow of single-driver drivers on the road section (i, j), so the traffic flow can be expressed as the flow of carpooling drivers between each OD pair rs and traffic of solo drivers sum express; Step 32: Convert travel time into travel time cost by introducing time value η in, represents the travel time cost of road section (i, j), η is the time value, that is, the amount of money corresponding to unit time, t ij is the travel time of road segment (i, j); Step 33: The fuel cost is calculated as follows: in, represents the fuel cost of road section (i,j), τ f is the fuel cost per unit distance during driving, l ij is the length of the road segment (i, j); Step 34: The inconvenience cost is calculated as follows: in, represents the inconvenience cost of carpooling on road section (i, j); τ u Indicates the inconvenience fee when sharing a ride with a stranger. represents the average number of passengers per vehicle on the road section (i, j) between OD and RS, represents the number of carpooling drivers on the road section (i, j) between OD pair rs, represents the number of passengers sharing a ride on the road section (i, j) between the OD pair rs, and Cap is the maximum number of passengers per vehicle; Step 35: Calculate the fee τ that the carpooling passenger needs to pay to the carpooling driver ij , the cost is related to the length l of the road segment (i,j) ij There is a linear positive correlation, the linear relationship coefficient is ρ≥0, and the calculation formula is as follows: Among them, τ ij The fee that each carpool passenger needs to pay to the carpool driver, ij is the length of the road section (i, j), ρ is the fee to be paid per unit length; Step 36: Calculate rideshare driver earnings in, represents the income of each rideshare driver; Step 37: Calculate the travel costs of different travelers: The travel cost of a single driver is composed of two parts: travel time cost and fuel cost; the travel cost of a carpool driver is composed of four parts: travel time cost, fuel cost, inconvenience cost and driver income; the travel cost of a carpool passenger is composed of three parts: travel time cost, inconvenience cost and the fee that the passenger needs to pay to the carpool driver; in, represents the travel cost of a single driver, represents the travel cost of the carpool driver, represents the travel cost of carpooling passengers.

3. A method for allocating carpooling traffic flow according to claim 2, characterized in that: In step 34, When To avoid this problem, the average number of passengers can be regarded as the optimal solution of the following quadratic programming: Among them, O is the independent variable, which represents the number of passengers per vehicle. represents the number of carpooling drivers on the road section (i, j) between the OD pair rs, represents the number of passengers sharing a ride on the segment (i, j) between the OD pair rs; The complementary conditions corresponding to the quadratic programming are as follows, and the average number of passengers can be solved using the following complementary formula: in, represents the average number of passengers on the OD-RS link (i, j), For and Constraints The corresponding multiplier, For and Constraints The corresponding multiplier, Cap, is the maximum number of passengers per vehicle.

4. A method for allocating carpooling traffic flow according to claim 1, characterized in that: The sub-steps of step 4 are as follows: Step 41: Quantity relationship constraint condition: limits the quantity relationship between carpooling passengers and carpooling drivers with the same origin and destination pair on the road segment (i, j); in, represents the number of carpooling drivers on the road section (i, j) between the OD pair rs, represents the number of passengers sharing a ride on the segment (i, j) between the OD pair rs; For The multiplier corresponding to the quantitative relationship is For The corresponding multiplier; Cap is the maximum number of passengers per vehicle; The generalized road segment travel costs of various types of travelers are as follows: in, represents the generalized travel cost of a single driver, represents the generalized travel cost of the carpooling driver, Express the generalized travel costs of carpool passengers; represents the travel cost of a single driver, represents the travel cost of the carpool driver, travel costs for carpool passengers; Step 42: UE equilibrium constraint: In the user equilibrium (UE) state, if a segment (i, j) is on the shortest path from node r to the end node s and carries traffic, then its segment travel cost should be equal to the minimum cost from node i to node j on OD pair rs, as follows: in, represents the node potential of node j between OD and RS on the single driver network layer in the extended network, represents the node potential of node i between OD and RS in the extended network, represents the minimum travel cost between node j and node i between OD pair rs on the network layer of the single driver in the extended network; represents the node potential of node j between OD pairs rs on the carpooling driver network layer in the extended network, represents the node potential of node i between OD and RS in the carpooling driver network layer in the extended network, represents the minimum travel cost between node j and node i between OD pair rs on the carpool driver network layer in the extended network; represents the node potential of node j between OD pairs rs on the shared passenger network layer in the extended network, represents the node potential of node i between OD pairs rs on the shared passenger network layer in the extended network, represents the minimum travel cost between node j and node i between OD pairs rs on the shared passenger network layer in the extended network; Step 43: The travel cost of the virtual road segment is zero, and the formula is as follows: The UE balancing constraint expression on the virtual starting section is: in, represents the node potential of the virtual starting node between OD and RS in the extended network, represents the number of independent drivers on the virtual starting section connecting the virtual starting node between the OD pair RS and the independent driver network layer starting node in the extended network, represents the node potential of the starting node on the network layer of the individual driver between the OD pair RS in the extended network, represents the minimum travel cost between the virtual starting node between OD pairs in the extended network and the starting node on the single driver network layer; represents the number of carpool drivers on the virtual starting section connecting the virtual starting node between the OD pair RS in the extended network and the starting node of the carpool driver network layer, represents the node potential of the starting node on the network layer of the shared driver between OD pairs RS in the extended network, represents the minimum travel cost between the virtual starting node between OD pairs in the extended network and the starting node on the carpooling driver network layer; represents the number of carpooling passengers on the virtual starting section connecting the virtual starting node between the OD pair RS in the extended network and the starting node of the carpooling passenger network layer, represents the node potential of the starting node on the passenger network layer between OD pairs RS in the extended network, represents the minimum travel cost between the virtual starting node between OD pairs in the extended network and the starting node on the shared passenger network layer; Step 44: Traffic and demand constraints: Satisfy the traffic conservation constraint, that is, the difference between the flow inflow and the flow outflow from any intermediate node should be 0; and the virtual start node and the virtual end node need to satisfy the demand conservation constraint; the set of all road segments in the entire extended network is recorded as The travel demand between OD and RS is recorded as m represents the set of three types of travel modes: single drivers, carpool drivers, and carpool passengers. represents the number of m-th travel modes on the road segment (i, j) between OD pair RS, represents the number of m-th travel modes on the road segment (k, i) between the OD pair rs; represents the total traffic demand of OD on the virtual starting node r between rs, represents the total traffic volume flowing out of the virtual starting node r between OD pairs rs; It represents the total traffic volume flowing into the virtual termination node s between OD pair rs.

5. A carpooling traffic flow distribution system, characterized by: The system can be used to implement a method for allocating carpooling traffic flow as described in any one of claims 1 to 4, and the system comprises: an expansion network module, a road capacity calculation module, a cost calculation module, a constraint module and a solution module; Expanded network module: The original traffic network is replicated into three layers of networks according to the travel modes available to travelers in the traffic network, namely: a single driver network layer, a carpool driver network layer, and a carpool passenger network layer; Symbols are used to represent the travel modes of traffic travelers and the collection of nodes and road segments in each layer of the network: The three-layer network is connected by introducing virtual road segments, virtual start nodes and virtual end nodes; and symbols are used to represent the set of virtual road segments, the set of virtual start nodes and the set of virtual end nodes; Road capacity calculation module; calculates road capacity; Cost calculation module: used to calculate travel time, travel time cost, fuel cost, inconvenience cost, cost that carpooling passengers need to pay to carpooling drivers, income of carpooling drivers and travel costs of different travelers; Constraint module: establishes OD-based constraint relationships, including: quantity relationship constraints, UE balance constraints, and traffic and demand constraints; Solution module: Use the PATH solver in GAMS to solve.

6. A computer device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, a method for allocating shared travel traffic flow as claimed in one of claims 1 to 4 is implemented.

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