Generalized Travel Cost Research Articles

Research on Passenger Flow Assignment of Integrated Cross-Line and Skip-Stop Operation between State Railway and Suburban Railway

The passenger flow assignment in the rail transit network is the basis for determining the passenger spatiotemporal distribution and train operation organization plan. In previous studies, the passenger flow assignment problem mainly focused on lines within the same rail system. Few studies focus on lines with the integrated mode of cross-line and skip-stop operation between state and suburban railway due to fewer cases in practice. In this study, passenger congestion and fare policy are taken into account in the generalized travel cost function, and a passenger flow assignment model based on the path-sized logit (PSL) model considering train capacity is proposed. Meanwhile, a schedule-based spatiotemporal digraph is established to search for the shortest spatiotemporal travel path. Furthermore, an improved method of successive averages (MSA) algorithm is designed to solve the proposed model. The proposed model is verified by a numerical example. The sensitivities of three main parameters which influence the results are also analyzed. The results show that the assignment model based on PSL is practicable in integrated operation mode. The higher the passenger’s familiarity with network information, the more accurate the assignment results. State trains are more attractive when the fare is lower than 0.5 CNY/km or the hourly wage is higher than 50 CNY/h.

Wages and accessibility – Evidence from Denmark

• This study estimates the agglomeration elasticity on Danish data of wages. • The decay parameter determining the distance weighting is estimated from the data. • The agglomeration elasticity is very robust to different estimation strategies. We estimate the elasticity of wages in Denmark with respect to the accessibility to jobs. This elasticity is used as an estimate for the productivity effects of transport infrastructure changes and is to be applied in calculations of the wider economic benefits of transport in policy appraisals in Denmark. The accessibility is a measure of economic density and is calculated as a weighted number of accessible jobs, where the weights are determined by a decreasing function of the generalised travel cost. The decay parameter determining the distance weighting is estimated from the data. We use a combination of different approaches, to control for selection bias and test the robustness of the results. The estimates are robust to the different estimation strategies. Over all, the elasticity varies in the range 0.008–0.037, and the estimates from our preferred models vary in the range 0.025–0.029.

Estimation Markov Decision Process of Multimodal Trip Chain between Integrated Transportation Hubs in Urban Agglomeration Based on Generalized Cost

An efficient multimodal transportation network is crucial to the development of urban agglomeration. Rapid transfer of travelers between integrated transportation hubs is essential for long-distance multimodal trip chains. The Markov Decision Process framework was estimated to explore the optimal transfer trip chain of different income groups, given that the states are considered nodes between hubs, the reward functions are calculated by using the generalized travel cost between states after travelers make action decision, and the actions between states contain bus, subway, taxi, and walk. The optimal trip chain can be obtained through a value iteration algorithm. In the case study, multimodal transfer trip chains of different types between Beijing Capital International Airport and Beijingxi Station in Beijing-Tianjin-Hebei urban agglomeration were constructed by MDP to compare the optimal trip chains of various groups. The findings of this study are as follows: (1) long-distance travelers always prefer to choose the unimodal fewer transfers trip chain between hubs; (2) long-distance travelers are more likely to choose the trip chain with more transfers more than long waiting time; (3) individual income difference affects the generalized cost of trip chains and also influences the optimal choice of trip chain through the MDP framework. One potential application of this study is to complement the research on the transfer behavior of multimodal trip chains in long-distance travel, which can be used to help management alleviate the excessive pressure of passenger flow between integrated hubs due to the sudden colossal travel flow during severe weather days or holidays.

General attraction analysis on high-speed rail and aviation between Beijing and Shanghai, China

High-speed rail and aviation are the two most popular modes of transportation between Beijing and Shanghai. Based on the existing literature, this paper summarized seven key influencing factors of the high-speed rail and civil aviation comprehensive attraction from the Beijing-Shanghai corridor. Furthermore, we constructed five single index models to quantify them. By analysing the logical relationships among various indicators, the generalized travel cost function with different modes of transportation and different user types under different seasons is finally obtained. To ensure the reliability of the analysis results, the collected data were used to calibrate most of the parameters of the generalized cost function model. After that, a series of sensitivity analysis are conducted. The results show that the attractiveness ranking of these two transportation modes is influenced by the purpose of the trip, the characteristics of the passengers, and changes in the season. This paper may offer some valuable references for aviation and railway transport companies.

Multi-Objective Optimization of Differentiated Urban Ring Road Bus Lines and Fares Based on Travelers’ Interactive Reinforcement Learning

This paper proposes a new multi-objective bi-level programming model for the ring road bus lines and fare design problems. The proposed model consists of two layers: the traffic management operator and travelers. In the upper level, we propose a multi-objective bus lines and fares optimization model in which the operator’s profit and travelers’ utility are set as objective functions. In the lower level, evolutionary multi agent model of travelers’ bounded rational reinforcement learning with social interaction is introduced. A solution algorithm for the multi-objective bi-level programming is developed on the basis of the equalization algorithm of OD matrix. A numerical example based on a real case was conducted to verify the proposed models and solution algorithm. The computational results indicated that travel choice models with different degrees of rationality significantly changed the optimization results of bus lines and the differentiated fares; furthermore, the multi-objective bi-level programming in this paper can generate the solution to reduce the maximum section flow, increase the profit, and reduce travelers’ generalized travel cost.

Cruising for Parking with Autonomous and Conventional Vehicles

Parking is a cumbersome part of auto travel because travelers have to search for a spot and walk from that spot to their final destination. This conventional method of parking will change with the arrival of autonomous vehicles (AV). In the near future, users of AVs get dropped off at their final destination and the occupant-free AVs search for the nearest and most convenient parking spot. Hence, individuals no longer bear the discomfort of cruising for parking while sitting in their vehicle. This paper quantifies the impact of AVs on parking occupancy and traffic flow on a corridor that connects a home zone to a downtown zone. The model considers a heterogeneous group of AVs and conventional vehicles (CV) and captures their parking behavior as they try to minimize their generalized travel costs. Insights are obtained from applying the model to two case studies with uniform and linear parking supply along the corridor. We show that (i) CVs park closer to the downtown zone in order to minimize their walking distance, whereas AVs park farther away from the downtown zone to minimize their parking search time, (ii) AVs experience a lower search time than CVs, and (iii) higher AV penetration rates reduce travel costs for both AVs and CVs.

Simulation of fixed versus on-demand station-based feeder operations

The paper develops a simulation model and evaluates fixed versus on-demand operational designs of a station-based automated feeder service. The evaluation considers the operational cost and average passenger level-of-service trade-offs as well as distributional differences in waiting times. Two case studies are used to evaluate such trade-offs under different fleet compositions; (1) a simple circular network feeder service; (2) a case based on a real-world coordinated branched service in Stockholm, combining fixed-line services on the trunk portion with a flexible feeder service on the branches. Results for the circular network indicate that there are benefits in utilizing an on-demand operational policy for the lowest and highest demand levels tested. When fixed service capacity is exceeded, it is found that there are potential benefits in on-demand operations with respect to average level-of-service, as well as delivering a more even distribution of passenger waiting times. Results for the real-world case show that combining DRT on branches with fixed services on the trunk improves the overall median waiting times for all DRT scenarios and provides substantial improvements for passengers on the trunk, at the cost of more variable, and less equitable waiting times on the branches. For larger fleet sizes, generalized travel costs are reduced with and without rebalancing and level-of-service provided to branch-to-branch passengers is improved considerably by rebalancing idling vehicles to branch end-stops. The case studies demonstrate the usefulness of the simulation framework in evaluating trade-offs between fixed and on-demand service design variables and their effects on disaggregate level-of-service provided for stop-based feeder services.

Why they don't choose bus service? Understanding special online car-hailing behavior near bus stops

People are more likely to choose to take a bus for travel theoretically if both the origin and destination are located near bus stops. However, many of these trips are now replaced by online car-hailing service in China. This study makes the first attempt to look into this special hailing behavior by conducting a contrast analysis between hailing trip and its corresponding bus journey with the same origin and destination. We proposed an identification approach to classify the special hailing trips into four types of hailing behaviors with various hailing willingness. Structural equation modeling is then used to explore the impacts of land use characteristics, features of transport facilities and hailing ridership characteristics on the performance of special hailing behavior. Based on the results, 10.86 percent of special hailing trips have origins and destinations that are located within 100 m distance of the bus stop. Imbalance travel demand for special hailing at different periods of the day indicates the time-varying characteristic, which reaches its highest level in the afternoon. Especially through the major mobility trends of these trips, the spatial patterns of special hailing behavior can be divided into two regimes (i.e. urban and suburban areas) corresponding to the agglomeration area of varied social activities and residential areas. The generalized travel costs of bus and online car-hailing reflect the hailing willingness of travelers to some extent. People face the tradeoff between the two travel modes and tend to choose instead to use online car-hailing in different situations, and the SEM results support this. Notably, the accessibility of bus stops and users' bus travel experience show significant negative effects on special hailing behavior, and the need to transfer during a bus journey can particularly influence a traveler's initiative to take a bus. The findings provide insights into the special online car-hailing usage patterns at bus stop level and its role in urban transport, which can support accurate planning and upgrading of sustainable public transit to increase competitiveness at the big picture.

Replacing short-medium haul intra-European flights with high-speed rail: Impact on CO2 emissions and regional accessibility

Over the last years, the exponential growth of air traffic has led to an increase in aviation-related negative externalities, raising the issue of sustainable growth in air transport to the forefront of policymaker and national government debates. One of the strategies designed to reverse this trend is to enable modal shift toward greener transport modes where technically possible. Our research quantifies, at a pan-European level, the possible impact of a policy of cancellations of short-medium-haul air routes that are currently effectively served by alternative transport modes, and mainly by high-speed rail. Following recently introduced policy initiatives, we analyze route substitutability based on not only the increase in travel time faced by passengers due to the enforced modal shift, but also the corresponding change in their generalized travel costs. At a macro-European level, our analysis reveals that about 26.5 million (3.02% of intra-European) offered seats may be cancelled and substituted with alternative trips without any significant increase in travel time for passengers. The French domestic market and flag carrier Air France lead the standings both in terms of the number of substitutable offered seats and potential CO2 savings. Moreover, analyzing the impacts at the regional level, we outline that this policy would preserve disadvantaged regions by placing the burden of reducing emissions from aviation mainly on areas already efficiently served by alternative transport modes. Overall, the replacement of short-medium haul routes would undoubtedly mark a step toward meeting medium-long-term targets of greenhouse gas emission reduction. Eventually, we discussed a number of key issues that policymakers need to address for a successful and not-myopic implementation of the policy.

Modeling and managing the morning commute problem with park-and-ride-sharing

In this paper, park-and-ride-sharing (P&RS) is proposed to manage morning peak hour congestion in a monocentric linear city, where there is a multilane highway with a single bottleneck connecting the residential area and the central business district (CBD). To realize ride-sharing matching, a ride-sharing parking lot (RSPL) and a ride-sharing meeting point (RSMP) are set up somewhere between the origin and the bottleneck. To encourage ride-sharing participation, the lanes of the highway are physically divided into high occupancy vehicle (HOV) and general purpose (GP) lanes for only ride-sharing vehicles and non-ride-sharing vehicles, respectively. The user equilibrium principle in terms of generalized travel cost is adopted to formulate commuters’ mode choice and arrival time choice at the RSMP. It is demonstrated that there exist three possible equilibrium ride-sharing matching patterns and three possible equilibrium traffic flow patterns. All possible equilibrium ride-sharing matching and traffic flow patterns are analytically derived. In addition, to minimize total system cost (TSC), three break-even parking charge schemes are designed under the case that all parking lots are managed by the government. The optimal allocation scheme of bottleneck capacity to HOV lanes under each parking charge scheme is analytically derived. Finally, numerical examples are provided to illustrate the properties of the proposed bottleneck model with P&RS and the effectiveness of the designed parking charge schemes.

Competition between shared autonomous vehicles and public transit: A case study in Singapore

Emerging autonomous vehicles (AV) can either supplement the public transportation (PT) system or compete with it. This study examines the competitive perspective where both AV and PT operators are profit-oriented with dynamic adjustable supply strategies under five regulatory structures regarding whether the AV operator is allowed to change the fleet size and whether the PT operator is allowed to adjust headway. Four out of the five scenarios are constrained competition while the other one focuses on unconstrained competition to find the Nash Equilibrium. We evaluate the competition process as well as the system performance from the standpoints of four stakeholders—the AV operator, the PT operator, passengers, and the transport authority. We also examine the impact of PT subsidies on the competition results including both demand-based and supply-based subsidies. A heuristic algorithm is proposed to update supply strategies for AV and PT based on the operators’ historical actions and profits. An agent-based simulation model is implemented in the first-mile scenario in Tampines, Singapore. We find that the competition can result in higher profits and higher system efficiency for both operators compared to the status quo. After the supply updates, the PT services are spatially concentrated to shorter routes feeding directly to the subway station and temporally concentrated to peak hours. On average, the competition reduces the travel time of passengers but increases their travel costs. Nonetheless, the generalized travel cost is reduced when incorporating the value of time. With respect to the system efficiency, the bus supply adjustment increases the average vehicle load and reduces the total vehicle kilometers traveled measured by the passenger car equivalent (PCE), while the AV supply adjustment does the opposite. The results suggest that PT should be allowed to optimize its supply strategies under specific operation goals and constraints, and AV operations should be regulated to reduce their system impacts, including potentially limiting the number of licenses, operation time, and service areas, which makes AV operate in a manner more complementary to the PT system. Providing subsidies to PT results in higher PT supply, profit, and market share, lower AV supply, profit, and market share, and increased passenger’s generalized cost and total system PCE.

Optimizing Train Timetable Based on Departure Time Preference of Passengers for High-Speed Rails

Passengers would like to choose the most suitable train based on their travel preferences, expenses, and train timetable in the high-speed railway corridor. Meanwhile, the railway department will constantly adjust the train timetable according to the distribution of passenger flows during a day to achieve the optimal operation cost and energy consumption saving plan. The question is how to meet the differential travel needs of passengers and achieve sustainable goals of service providers. Therefore, it is necessary to design a demand-oriented and environment-friendly high-speed railway timetable. This paper formulates the optimization of train timetable for a given high-speed railway corridor, which is based on the interests of both passengers and transportation department. In particular, a traveling time-space network with virtual departure arc is constructed to analyze generalized travel costs of passengers of each origin-destination (OD), and bilevel programming model is used to optimize the problem. The upper integer programming model regards the minimization of the operating cost, which is simplified to the minimum traveling time of total trains, as the goal. The lower level is a user equilibrium model which arranges each OD passenger flow to different trains. A general advanced metaheuristic algorithm embedded with the Frank–Wolfe method is designed to implement the bilevel programming model. Finally, a real-world numerical experiment is conducted to verify the effectiveness of both the model and the algorithm.

Why China must build Sichuan-Tibet railway: From the perspective of regional comprehensive transportation network optimization

We not only firstly applied the theory of hub-and-spoke network to the field of integrated transportation network planning, but also combined our proposed method with Sichuan-Tibet railway, one of super large projects in China, to discuss the optimization and the layout of hub-and-spoke integrated transportation network along the Sichuan-Tibet railway after it is put into operation in the future and put forward some directional policy recommendations. In our study, we have made clear the topological structure of the multi hub and single allocation hybrid hub-and-spoke integrated transportation network in the passenger transportation corridors, established the integer programming model aiming at the minimum generalized travel cost in the network, and we designed the simulated annealing algorithm to solve this problem. In the empirical study, we find that if 5 nodes are selected as hub nodes in hub-and-spoke integrated transportation network, the generalized cost of network travel will be minimized and these specific location of 5 hub nodes can be determined by the selecting principle of hub nodes location, which we proposed in our study. The simulated annealing algorithm can help us to find the connection relationship between nodes. Then we can achieve three types of hub-and-spoke integrated transportation network layout patterns with railway, highway and aviation as the hub nodes. Though further comparative analysis, we find that it is more feasible to choose the integrated transportation network with railway nodes as the hub in transportation organization. Based on this understanding, we put forward policy recommendations on transportation organization to support high-quality planning and operation of integrated transportation network to Sichuan Tibet region in China in the future.

ANALYSIS OF COMMUTERS' PERCEPTIONS ABOUT CARPOOLING SERVICE: A CASE STUDY IN LAHORE

The increase in urban population and private vehicle ownership has resulted in traffic congestion on road networks. The traffic congestion tends to increase social cost in terms of increased travel delays, road crashes and environmental pollution. Traffic congestion also increases the generalized travel cost of road users. There is a need to look for alternative travel options to ensure sustainable development of the society and transportation infrastructure. This study aims to identify the significant relationships between the socio-economic demographics (SEDs) of the travelers and their intentions with carpooling. The data was collected with the help of a questionnaire survey. This survey was conducted in Lahore city and three hundred and ninety four samples were obtained. The data was analyzed using frequency analysis and ordered probit regression analysis. The results revealed that the traveler’s marital status, education, daily trip distance, current travel mode, household income, car ownership and possession of a driving license had a significant influence on their willingness to adopt a carpooling alternative. Besides the trip, purpose of carpooling and the number of persons with whom to share a ride had significant correlations with carpooling. These significant attributes implicate that travelers’ specific characteristics play an important role in their decision to carpool. Carpooling programs are required to design, seeking the significant characteristics of travelers in the context of Lahore city as well as in other regions. These findings provide useful information to the transport planners and decision-makers in designing the transportation policies related to carpooling strategies.

CPT Model-Based Prediction of the Temporal and Spatial Distributions of Passenger Flow for Urban Rail Transit under Emergency Conditions

Emergencies have a significant impact on the passenger flow of urban rail transit. It is of great practical significance to accurately predict the urban rail transit passenger flow and carry out research on its temporal and spatial distributions under emergency conditions. Urban rail transit operating units currently use video surveillance information mainly to process emergencies and rarely use computer vision technology to analyze passenger flow information collected. Accordingly, this paper proposes a passenger flow-based temporal and spatial distribution model for urban rail transit emergencies based on the CPT. First, this paper clarifies the categories and classification of urban rail transit emergencies, analyzes the factors affecting passenger route selection, and establishes a generalized travel cost model for passengers under emergencies. Second, this paper establishes a passenger route choice behavior model for urban rail transit based on the cumulative prospect theory. Finally, taking Beijing as an example, this paper analyzes passenger travel behavior under emergencies based on multiple logistic regression models and analyzes the impact of emergencies on rail transit travel behavior. The research results show that the cumulative prospect theory can better describe the route choice behavior of rail transit passengers under emergencies than the existing models, and this model is of great significance for handling urban rail transit emergencies. The model proposed in this paper can provide a theoretical basis for the government and relevant departments to formulate traffic management measures.

Integrated demand response for congestion alleviation in coupled power and transportation networks

The increasing prevalence of electric vehicles (EVs) and emerging dynamic wireless charging (DWC) techniques have strengthened the interdependence between transportation networks (TNs) and power distribution networks (PDNs). Under the DWC mode, EV charging demand is shifted from residential plug-in charging to charging-while-driving during commuting hours, resulting in a simultaneous congestion in coupled networks. The present study addresses this issue by developing a bi-level integrated demand response (IDR) framework for alleviating congestion in coupled networks. At the upper level, an independent system operator aims to alleviate congestion by imposing the lowest possible traffic tolls and electricity tariffs. At the lower level, rational travelers in the TN schedule their routes and departure times according to traffic tolls and traffic conditions, yielding a multi-period user equilibrium state in which the generalized travel cost of users cannot be decreased by unilaterally changing routes or departure times. Simultaneously, load aggregators in the PDN schedule flexible power demands according to electricity tariffs to minimize total energy costs. The overall bi-level programming is reformulated into a single-level mathematical program with a complementarity constraint problem, which is efficiently solved as a sequence of relaxed non-linear programming problems by a specially designed algorithm. Numerical results demonstrated the effectiveness of the proposed IDR framework in alleviating congestion and reducing total procurement costs.

Effects of Link Capacity Reductions on the Reliability of an Urban Rail Transit Network

Link capacity reductions, which occur often, degrade the service quality and performance of urban rail transit (URT) networks. To measure the reliability of a URT network when link capacity reductions occur in a given time period, the passengers’ generalized travel cost (GTC) is computed and passengers are divided into three categories. The GTC considers here the crowding in trains, seat availability, and perceived travel time. Passengers whose relative increase in GTC on a URT is below or above a preset threshold belong to category I or II, respectively, while passengers who cannot travel on the URT due to insufficient capacities on their paths belong to category III. Passenger trips in categories I are acceptable since their GTC increases only slightly with link capacity reductions. The fraction of acceptable trip (FAT) and total GTC increase ratio (TGCR) in a given time period are defined here as the network’s reliability and unreliability metrics, respectively. The ratio of affected passenger trip (RAPT) is proposed to identify each line’s most critical links. The reliability and unreliability metrics of Wuhan’s URT network during evening peak hours are computed when the capacities of the most critical link or multiple most critical links are reduced. The results show that the proposed RAPT indicator is effective in identifying the most critical links that greatly affect the reliability and performance of a URT network. For capacity reductions on a line’s most critical link, the proposed method can determine the capacity reduction ratio corresponding to network’s high FAT and low TGCR as well as the priorities of lines needing emergency measures to maintain high network reliability and performance. For capacity reductions on critical links of multiple lines, the proposed method can identify the number of reduction links and the capacity reduction ratio that the network can withstand while maintaining its reliability and performance above a specified level.

Assessing transport policies for tourist mobility based on accessibility indicators

Tourism is a key sector in the national economies, representing a real asset for increasing the competitiveness and the world-wide visibility of a Country. In Italy, the widespread diffusion of the tourist heritage represents a great potential for the economic development but requires efforts to identify sustainable and seamless travel solutions, given the limited resources available for tourist mobility. The Italian National Plan of Tourist Mobility identifies in accessibility one of the key drivers for investment, and to this aim has developed a Planning Support System (PSS) to identify the investments to bridge up the accessibility gap of national tourist sites from the main airports, ports and railway stations (i.e. the “access gates” to the Country), either on the road network or using collective transport services. The PSS is based on the methodology presented in this paper, combining two concepts extensively studied in the literature, i.e. the generalized travel cost and the accessibility, in order to identify where and how to invest either to improve existing mobility services or to build new infrastructure. Given the number of tourist sites scattered over the national territory, the application of the proposed methodology to the Italian case study represents a relevant example of how accessibility measures can be applied in practice to link with policy goals and to identify planning priorities. The application is easily replicable and transferable at regional and local level.

Analysis of Beijing-Guangzhou High-Speed Railway Competitiveness Based on Generalized Travel Cost Model

After the completion of the Beijing-Guangzhou high-speed railway, this paper studies the market sharing rate of the normal-speed railway, high-speed railway and civil aviation aircraft in the Beijing-Guangzhou line, and the broad travel cost of passengers. Ticket price, speediness, safety, comfort, convenience and punctuality are selected as evaluation indexes. Combined with the improved Logit model, a multiple discrete choice model of passenger travel is established. Then this paper investigates the travel intention of passengers and the actual data needed for model indicators. At last, the share rate of various modes of transportation in the Beijing-Guangzhou under the circumstances of different distances and different time values is predicted, as well as the impact of air fares on the competitiveness of high-speed rail products.

Research on optimized design of road space in mixed sections of historical district: a case study of Xi’an, China

To solve the problems existing in most Chinese historic districts, such as incomplete traffic network planning and unreasonable spatial layout, this paper analyzes the spatial characteristics of motor vehicles in the mixed road section of a historical district and summarizes the application conditions and shortcomings of the model for calculating the Bolankerf lane width and re-calibrates the parameters of the model with the survey data, to determine the formula for calculating the width of motor lanes in different sections of roads. Furthermore, this paper establishes a game model of road space optimization for mixed sections of motor vehicles and non-motor vehicles with the goal of minimizing the generalized travel cost. Finally, by taking the Xiangzimiao historic district as the verification object, this paper draws from the Bolankerf model and the game model to determine the most reasonable road space division plan within blocks.