Demand-responsive transit circulator service network design

Commuter rail systems are being introduced into many urban areas as an alternative mode to automobiles for commuting trips. It is anticipated that the shift from the auto mode to rail mode can greatly help alleviate traffic congestion in urban road networks. However, the right-of-way of many existing commuter rail systems is usually not ideally located. Since the locations of rail systems were typically chosen long ago to serve the needs of freight customers, the majority of current commuter rail passengers have to take a non-walkable connecting trip to reach their final destinations after departing the most conveniently located rail stations. To make rail a more viable commuting option and thus more competitive to the auto mode, a bus feeder or circulator system is proposed for transporting passengers from their departing rail stations to final work destinations in a seamless transfer manner. The key research question with operating such a bus circulator system is how to optimally determine a bus route and stopping sequence for each circulating tour by using the real-time demand information. In this paper, we name this joint routing and stopping optimization problem the circulator service network design problem, the objective of which is to minimize the total tour cost incurred to bus passengers and operators with respect to minimizing the walk time of each individual bus passenger. A bi-level nonlinear mixed integer programming model is constructed and a tabu search method with different local search strategies and neighborhood evaluation methods is then developed for tackling the circulator service network design problem.     

Public bicycle as a feeder mode to rail transit in China: The role of gender,age, income,trip purpose,and bicycle theft experience

A marriage between public bicycle and rail transit presents new opportunities for sustainable transportation in Chinese cities. To examine determinants of public bicycle usage for rail transit access, an intercept survey of feeder mode choice among rail transit users was conducted near rail stations in Nanjing, China. Mode choice models were estimated with five feeder mode alternatives, including car, bus, walk, private bike, and public bike. By differentiating between public and private bicycle modes in the mode choice models, the study reveals the effects of personal demographics, trip characteristics, and station environments on public bicycle usage for rail transit access. Results show that female, older, and low-income rail commuters are less likely to use public bicycle to access rail transit. Rail commuters with bicycle theft experience and making school- or work-related trips are more likely to use public bicycle to access rail transit. Land use variables are largely insignificant in this study except that density shows a positive relationship with walking to rail transit. The results on demographic differences raise equity concerns when it comes to investing in public bicycle systems. Policy implications are discussed for Chinese cities to equitably boost public bicycle integration with rail transit.     

Active commuting in a university setting: Assessing commuting habits and potential for modal change

This paper describes the results of an online survey that examined commuting patterns, potential for change and barriers and motivators affecting transport decisions in a University population (n=1040 students, n=1170 staff). Overall, 21.5% of staff and 46.8% of students at The University of Western Australia regularly used active modes, and potentially an additional 30% of staff and students would switch to active modes. The results suggested that reducing barriers to using active modes, in particular reducing actual and perceived travel time by bus and bicycle would have the greatest impact on commuting patterns. Some policy applications appeared to hold particular promise, including an implementation of a subsidised public transport pass (U-Pass), increased student housing on or near campus, increased cost of parking, and improved bus services and cycle networks.     

Impacts of adverse weather on Arctic road transport

Arctic regions are geographically peripheral and characterized by cold climate, constantly changing weather conditions and strong seasonal variations. This article examines variations in road traffic volume due to adverse weather in an arctic region, a topic that has received little attention in the transportation literature. The subject of the case study is northern Norway's Saltfjellet mountain pass, which is part of European Highway 6 (Ev6). A succinct econometric structural equation model was used to test hypotheses regarding the impacts of fluctuations in temperature, precipitation and wind speed on passenger and freight traffic volumes. The findings indicate that there was some reduction in traffic volume during adverse weather, particularly with respect to passenger traffic. However, the day-to-day variations in traffic volumes were relatively low at the studied section of road, although it is known that generalized transport costs increase significantly in adverse weather due to delays related to poor driving conditions and closed roads. The studied region is rural with limited access to alternative routes or transport modes, thus making this portion of the road particularly important for the communities in the region. Hence, the road users have few other options than using this high-cost road in order to maintain their activities. The use of standardized parameters in transport models to predict the effect of adverse weather on traffic volume, would not be appropriate in the studied context. However, it is recommended that the benefits of reducing the extra costs that adverse weather impose on traffic are estimated and included in road-project assessment tools to capture the burden and strain imposed on road users. This to ensure that appropriate decisions are made regarding the development and improvement of transportation facilities, particularly in rural areas.     

Impacts on travel behaviour of Greater Manchester’s light rail investment (Metrolink Phase 1): evidence from household surveys and Census data

Household survey data from 1990 and 1993 and Census data from 1991 and 2001 are used to detect some short and medium term impacts on travel of the Metrolink light rail services which opened in 1992. Particular attention is paid to research design issues to try to isolate Metrolink’s impacts from those of other influences on travel behaviour. In the short term a more marked decline in the frequency of bus use is found in the Metrolink corridor compared with conventional rail and ‘no rail’ corridors. Changes in the frequency of rail use are more prominent in the Metrolink corridor, both to the highest frequency use but also to lower frequency use. Higher frequency rail use tends to be associated with respondents who have limited or no car availability, who are in employment, who are of non-manual social class and who are aged 18–44 years. Metrolink appears to have attracted at least as many former car users as former bus users, but the former car users tend to use the light rail services less frequently. Census commuting data suggest that, in the medium term, Metrolink has increased rail’s share of trips, especially to the city centre, contributed to the declining share of bus trips and may have helped to restrain work trips by car.     

Environmental impacts of commuting modes in Lisbon: A life-cycle assessment addressing particulate matter impacts on health

A life-cycle assessment of commuting alternatives is conducted that compares six transportation modes (car, bus, train, subway, motorcycle, and bicycle) for eight impact indicators. Fine particulate matter (PM_2.5) emissions and health impacts are incorporated in the assessment using intake fractions that differentiate between urban and nonurban emissions, combined with an effect factor. The potential benefits of different strategies for reducing environmental impacts are illustrated. The results demonstrate the need for comprehensive approaches that avoid problem-shifting among transportation-related strategies. Policies aiming to improve the environmental performance of urban transportation should target strategies that decrease local emissions, life-cycle impacts and health effects.     

Intermodal integration in air transportation: status quo, motives and future developments

Soaring air traffic, increasing urban expansion and airports operating at full capacity are reasons that have caused a discussion about improvements in airport landside access systems. One approach to better match customer demands and address airport congestion is to facilitate the intermodal integration of airports. Building on a survey on intermodal passenger air transportation, we elaborate on the current and future situation at major airports. Our findings indicate a high modal concentration and dependence on individual access modes. However, while airport managers intend to reduce the share of these modes, they plan to increase that of high-occupancy airport access modes. We analyze the underlying motives that cause airports to extend their connections to surface infrastructure. In a case study, we assess an intermodal best practice solution for the integration of air and rail.     

An investigation of the performance of urban rail transit systems on the corridor level: A comparative analysis in the American west

Since the 1980s, significant investments have been made in urban rail transit across the United States, particularly using light rail technology. Most of these light rail systems have been built in Sunbelt cities which no longer had legacy rail systems. As a result, they were constructed using a building blocks approach, being funded corridor by corridor. Most research, however, on urban rail performance has taken place at the system-wide level, leaving a significant gap at the level of the transit corridor. This research examined nineteen urban rail corridors in Denver, Salt Lake City, and Portland. A performance score was constructed for each corridor based upon ridership per mile, ridership growth, capital costs, and the cost of ongoing operations. These scores were then compared with the geographic profile of each corridor studied. Corridors in each city ranked high and low, with no city emerging as a clear frontrunner. More centrally-located corridors in each city registered the highest performance scores, while longer corridors in more peripheral locations had lower performance scores. Headways, population density, job density, walkability, and percentage renter occupied housing units were found to have a statistically significant relationship with high corridor performance, largely in line with previous studies, though median income, bus connections, and park and ride spaces were not found to increase performance in this study.     

铁路客运专线成本曲线分析

借鉴国内外客运专线资料,对铁路客运专线运输成本的特性及构成进行论述,并从速度目标值与客运量两方面分析对运输成本的影响,说明速度目标值直接影响客运专线的运输成本,而固定成本与客运量无关,变动成本与客运量成正比变化。     

Modeling bicycle crash costs using big data: A grid-cell-based Tobit model with random parameters

Bicyclists are among the most vulnerable road users in the urban transportation system. It is critical to investigate the contributing factors to bicycle-related crashes and to identify the hotspots for efficient allocation of treatment resources. A grid-cell-based modeling framework was used to incorporate heterogeneous data sources and to explore the overall safety patterns of bicyclists in Manhattan, New York City. A random parameters (RP) Tobit model was developed in the Bayesian framework to correlate transportation, land use, and sociodemographic data with bicycle crash costs. It is worth mentioning that a new algorithm was proposed to estimate bicyclist-involved crash exposure using large-scale bicycle ridership data from 2014 to 2016 obtained from Citi Bike, which is the largest bicycle sharing program in the United States. The proposed RP Tobit model could deal with left-censored crash cost data and was found to outperform the Tobit model by accounting for the unobserved heterogeneity across neighborhoods. Results indicated that bicycle ridership, bicycle rack density, subway ridership, taxi trips, bus stop density, population, and ratio of population under 14 were positively associated with bicycle crash cost, whereas residential ratio and median age had a negative impact on bicycle crash cost. The RP Tobit model was used to estimate the cell-specific potential for safety improvement (PSI) for hotspot ranking. The advantages of using the RP Tobit crash cost model to capture PSI are that injury severity is considered by being converted into unit costs, and varying effects of certain explanatory variables are accounted for by incorporating random parameters. The cell-based hotspot identification method can provide a complete risk map for bicyclists with high resolution. Most locations with high PSIs either had unprotected bicycle lanes or were close to the access points to protected bicycle routes.     

Environmental benefits of air–rail intermodality: The example of Madrid Barajas

The environmental impact of transport is a growing issue in transport infrastructure planning. The construction of a high-speed rail station at the Madrid Barajas Airport in Spain is an example of the integration of different transportation modes, with expected environmental benefits. We construct a model to assess modal choice and environmental benefits. The results show that with high-speed rail the number of people choosing air travel and the private car is reduced leading to important environmental benefits: a reduction of close to 5 kg of CO₂ per passenger, or 10% of all emissions on the corridor. Our results also show that increasing the cost of using the private car is picked up by air transport rather than high-speed rail, leading to an increase in total emissions.     

Mode choice behavior modeling of ground access to airports: A case study in Istanbul,Turkey

The increase in air transportation mode share, thereby the passenger traffic at airports has made the ground access to the airports more important in recent years. The aim of this study is to analyze the ground access mode choice to airports by using Multinomial Logit (MNL). In particular, our focus is on how transit areas of influence affect the mode choice for travelling to airports. Atatürk International Airport (IST) in Istanbul, Turkey was selected for the analyses and the investigated modes to access IST were automobile, drop-off, public transit, and taxi. The results showed that significant factors and variables included the trip distance to access IST, type of destination, trip cost to IST, automobile ownership status, employment status, travelling group size, location of the trip origin with respect to public transit influence, and time difference between the flight time and departure time to IST. It is also concluded that if the trip origin to IST was inside the influence areas of public transit, then public transit would be more likely to be chosen over other modes for accessing IST.     

Rail access charges and the competitiveness of high speed trains

This paper examines rail access charges for high speed trains on new high speed lines in Europe and the impact these have on the market position of high speed rail. It examines the latest evidence on the marginal infrastructure and external costs of high speed rail, finding that the best evidence is that these are both not more than 2 €/train-km. However, current legislation states that environmental costs should not be charged for unless they are charged for on competing modes. Mark ups based on Ramsey pricing principles might reasonably raise prices by 100–200%, given that infrastructure charges are only a part of the final price of rail. The paper then examines the actual prices charged in the main European countries operating high speed trains and the impact these are likely to have on traffic levels and mode split. It is found that mark ups often exceed even the optimal Ramsey levels, with a significant impact on rail volumes and market share. It is concluded that, whilst it is not surprising that governments wish to recover some of the construction costs of new high speed rail lines from users, they should consider carefully whether the level of charges is actually significantly reducing traffic on and benefits from these lines.     

Assessing intercity multimodal choice behavior in a Touristy City: A factor analysis

This paper investigates influential factors in passengers' intercity multimodal choice behaviors in a touristy city. By collecting large individual-level data through a comprehensive field survey that was carried out at the major transportation hubs in Xi'an, China, we studied four travel modes of the surveyed travelers in this touristy city, including air, high-speed rail, traditional passenger train, and express bus. For factor analysis, 12 variables, including not only individual-related attributes but also ticketing methods and mental perceptions, were used as the independent factors after the correlation analysis and collinearity test. The regression relationships between the travel mode choice and the independent variables were studied using Bayesian multinomial logistic regression. The results indicate that those 12 factors have significant and various influences on passengers' mode choices. In particular, travel distance, fare rate, intercity travel time per hundred kilometers, quality of service, accessibility of transportation hubs, and ticketing methods have influential contributions for explaining the choice decision-makings. The findings demystify the effects of several unexplored factors in intercity multimodal travel choice behaviors and shed new light on formulating traffic management strategies for service providers and decision-makers in practice.     

Impact of transalpine rail network disruptions: A study of the Brenner Pass

This work investigates the impact of sudden rail closures on transportation networks and the local industries affected. A decision support system is introduced, which automatically generates a rail network and simulates passenger and freight traffic. In case of rail closures, freight traffic is rerouted and resulting delays are calculated. Furthermore, the option to transship from rail to road at terminals is enabled. The model is tested using data originating from a major transalpine rail corridor, the ‘Brenner Pass’, which connects Austria and Italy. Results show rail links which are critical and the impact of various disaster scenarios is compared.     

Freight transportation demand elasticities: a geographic multimodal transportation network analysis

This paper presents direct and cross-elasticity estimates of the demands for three freight transportation modes: rail, road and inland waterways. They are computed for 10 different categories of goods with a detailed multimodal network model of Belgian freight transports. The model, which minimises the generalised cost of transportation tasks defined by O-D matrices, assigns traffic flows to the different modes, transport means and routes. Successive simulations with different relative costs permit the computation of specific arc-elasticities. In contrast with the usual methodologies, the present methodology is not based on a statistical analysis of disaggregate data on actual modal choices and transport tariffs. This is a particularly useful feature since such data are mostly not available for freight transports in Europe. Furthermore, it fully takes into account the detailed characteristics of the network, all available routes and combinations of modes, as well as the specific localisation of activities within the network. Its estimates are compared with previously published estimates, and, in particular, with Abdelwahab's results published (1998) in this journal.     

Optimal traffic calming: A mixed-integer bi-level programming model for locating sidewalks and crosswalks in a multimodal transportation network to maximize pedestrians’ safety and network usability

We study the effect that installing sidewalks and crosswalks, as traffic calming facilities, has on the safety and usability of a transportation network with automobile, public transit and walking as modes of transportation. A mathematical programming model is proposed for this problem whose objective is to minimize the safety hazard for pedestrians and the total transportation cost of the network. We utilize a customized greedy heuristic and a simulated annealing algorithm for solving the problem. The computational results indicate that installing sidewalks and crosswalks at proper locations can reduce the overall transportation cost and improve pedestrians’ safety.     

“产城融合”模式下准东开发区通勤轨道交通规划布局方案研究

准东开发区"产城融合"要求产业区与生活服务区空间布局合理,通过高效的轨道交通系统,实现职工的通勤需求。基于准东开发区"产城融合"模式、准东开发区及周边县市现状、交通发展状况,分析通勤旅客出行特征及存在问题。依据客流量预测结果、交通方式选择,结合准东开发区通勤轨道交通规划目标及布局,提出通勤轨道交通规划布局方案,有利于提升准东开发区与周边县市交通功能,改善开发区与周边县市的出行条件,压缩准东开发区和周边县市生活区的时空距离。     

The assessment of the EU–US Open Skies Agreement: The counterfactual and other difficulties

The advent of the EU–US Open Skies Agreement has been widely anticipated. A number of consequences have been predicted, for example, impacts on fares, on passenger volumes, choice and on consumer welfare. Airline costs are also predicted to fall as a result of increased competitiveness and increased cooperation among airlines. In the short period since the implementation of the Agreement, it is relatively easy to assess the supply-side changes that have been made, but more difficult to make wider judgements. For example, can traffic growth be attributed to Open Skies and does airline and alliance market power result in less fare flexibility with consequently less influence on changes in passenger volumes? Have airline costs changed and what has been the source of the savings? This paper offers some insight into the data that will be required to make these and other wider judgements and discusses some methodological difficulties.