考虑用户偏好的共享汽车混合运营模式优化

针对共享汽车运营商的油车和电车混合车队调度问题，本文将自由流动式和站点借还式两种运营模式相结合，提出考虑用户用车类型偏好的共享汽车系统优化模型。模型为油车和电车车队分别设置了自由流动式和站点借还式的运营模式，并进行运营范围决策、站点选址和车辆调度优化；运营商优先满足用户的用车类型偏好选择，对无法满足偏好的用户进行补贴。根据优化模型基本特征，设计基于梯度的启发式求解方法，对大规模非线性混合整数规划模型进行求解；针对案例区域，比较有无补贴的混合车队模式和单一车队模式的优化结果。结果表明：相比无补贴模式，有补贴模式能够鼓励偏好燃油汽车的用户更多地使用电动汽车，需求满足率从73.4%提高到78.2%，运营商利润提高了46.4%；相比单一类型车队，混合车队能够吸引更多用户使用共享汽车，用户需求数提高了40.6%。     

The impact of automated transit,pedestrian, and bicycling facilities on urban travel patterns

This article reports on an integrated modeling exercise, conducted on behalf of the US Federal Highway Administration, on the potential for frequent automated transit shuttles (‘community transit’), in conjunction with improvements to the walking and cycling environment, to overcome the last-mile problem of regional rail transit and thereby divert travelers away from car use. A set of interlocking investigations was undertaken, including development of urban visualizations, distribution of a home-based survey supporting a stated-preference model of mode choice, development of an agent-based model, and alignment of the mode-choice and agent-based models. The investigations were designed to produce best-case estimates of the impact of community transit and ancillary improvements in reducing car use. The models in combination suggested significant potential to divert drivers, especially in areas that were relatively transit-poor to begin with.     

Determining the Monetary Value of Quality Attributes in Freight Transportation Using a Stated Preference Approach

It is commonly accepted that the modal choice of a shipper is influenced not only by the pure economic attributes of transportation – time and cost – but also by more qualitative factors. These quality attributes relate to frequency, reliability, flexibility, transport duration and risk of loss or damage; they are usually difficult to quantify in monetary terms. Different techniques exist that help to understand better how these different quality attributes of freight transportation influence modal choice. In this paper we apply a stated preference design. Using real business data, the aim is then to derive partial utility functions that allow us to calculate monetary values for these different quality attributes.     

Consumers’ willingness to pay for alternative fuel vehicles: A comparative discrete choice analysis between the US and Japan

This paper conducts a comparative discrete choice analysis to estimate consumers’ willingness to pay (WTP) for electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) on the basis of the same stated preference survey carried out in the US and Japan in 2012. We also carry out a comparative analysis across four US states. We find that on average US consumers are more sensitive to fuel cost reductions and alternative fuel station availability than are Japanese consumers. With regard to the comparative analysis across the four US states, consumers’ WTP for a fuel cost reduction in California is considerably greater than in the other three states. We use the estimates obtained in the discrete choice analysis to examine the EV/PHEV market shares under several scenarios. In a base case scenario with relatively realistic attribute levels, conventional gasoline vehicles still dominate both in the US and Japan. However, in an innovation scenario with a significant purchase price reduction, we observe a high penetration of alternative fuel vehicles both in the US and Japan. We illustrate the potential use of a discrete choice analysis for forward-looking policy analysis, with the future opportunity to compare its predictions against actual revealed choices. In this case, increased purchase price subsidies are likely to have a significant impact on the market shares of alternative fuel vehicles.     

Rewarding rush-hour avoidance: A study of commuters’ travel behavior

Spitsmijden, peak avoidance in Dutch, is the largest systematic effort to date to study, in the field, the potential of rewards as a policy mean for changing commuter behavior. A 13 week field study was organized in The Netherlands with the purpose of longitudinally investigating the impacts of rewards on commuter behavior. Different levels and types of rewards were applied and behavior was tracked with state-of-the art detection equipment. Based on the collected data, which included also pre and post-test measurements, a mixed discrete choice model was estimated. The results suggest that rewards can be effective tools in changing commuting behavior. Specifically rewards reduce the shares of rush-hour driving, shift driving to off-peak times and increase the shares of public transport, cycling and working from home. Mediating factors include socio-demographic characteristics, scheduling constraints and work time flexibility, habitual behavior, attitudes to commuting alternatives, the availability of travel information and even the weather. The success of this study has encouraged adoption of rewards, as additional policy tools, to alleviate congestion, especially during temporary road closures.     

Door-to-door travel times in RP departure time choice models: An approximation method using GPS data

A common way to determine values of travel time and schedule delay is to estimate departure time choice models, using stated preference (SP) or revealed preference (RP) data. The latter are used less frequently, mainly because of the difficulties to collect the data required for the model estimation. One main requirement is knowledge of the (expected) travel times for both chosen and unchosen departure time alternatives. As the availability of such data is limited, most RP-based scheduling models only take into account travel times on trip segments rather than door-to-door travel times, or use very rough measures of door-to-door travel times. We show that ignoring the temporal and spatial variation of travel times, and, in particular, the correlation of travel times across links may lead to biased estimates of the value of time (VOT). To approximate door-to-door travel times for which no complete measurement is possible, we develop a method that relates travel times on links with continuous speed measurements to travel times on links where relatively infrequent GPS-based speed measurements are available. We use geographically weighted regression to estimate the location-specific relation between the speeds on these two types of links, which is then used for travel time prediction at different locations, days, and times of the day. This method is not only useful for the approximation of door-to-door travel times in departure time choice models, but is generally relevant for predicting travel times in situations where continuous speed measurements can be enriched with GPS data.     

Transshipment hub port selection for shipping carriers in a dual hub-port system

ABSTRACT

This paper investigates the factors affecting transshipment (T/S) hub port selection by a feeder port and helps shipping carriers make a decision about T/S hub port selection in a dual hub-port system. By employing established evaluation factors, a case study is conducted to weigh the priority of factors and to select an alternative T/S hub port, such as between the Shanghai and Ningbo ports from the Nanjing feeder port in the Yangtze River delta (YRD). A combined multi-criteria decision-making (MCDM) framework utilizing the analytic hierarchy process (AHP) and the consistent fuzzy preference relations (CFPR) method is employed to both reduce the number of pairwise comparisons by AHP and to obtain experts’ knowledge in the decision-making process. The result indicates that the cost, availability of hub port’s space allocation, and the connectivity between feeder port and hub port are crucial factors for T/S hub port selection by shipping carriers. In the case study, Shanghai is selected as the T/S hub port from the Nanjing feeder port. Nevertheless, Ningbo port has the advantage of cost, and if the relationship with feeder port can be improved, Ningbo port would be preferred over Shanghai as a T/S hub port for shipping carriers in a dual hub-port system.     

Stated preference analysis of travel choices: the state of practice

Stated preference (SP) methods are widely used in travel behaviour research and practice to identify behavioural responses to choice situations which are not revealed in the market, and where the attribute levels offered by existing choices are modified to such an extent that the reliability of revealed preference models as predictors of response is brought into question. This paper reviews recent developments in the application of SP models which add to their growing relevance in demand modelling and prediction. The main themes addressed include a comparative assessment of choice models and preference models, the importance of scaling when pooling different types of data, especially the appeal of SP data as an enriching strategy in the context of revealed preference models, hierarchical designs when the number of attributes make single experiments too complex for the respondent, and ways of accommodating dynamics (i.e. serial correlation and state dependence) in SP modelling.An earlier modified version was presented as the keynote address to the 1993 National Conference on Tourism Research, held at the University of Sydney, 19 March 1993. The comments of Jordan Louviere, Lester Johnson, Paul Hooper, W.G. Waters II and Mark Bradley are appreciated.     

Stated adaptation surveys and choice process: Some methodological issues

The "Stated Adaptation" survey is an interactive technique which allows us to obtain a clearer picture of the attitudes and behaviours of individuals when confronted with hypothetical situations, in particular inexperienced travel conditions. This method makes use of a simulation game whose purpose is to explore on small samples individuals' choice processes when selecting between the different transport alternatives which are available to them. This paper describes how gaming-simulation is designed, with reference to the issues tackled by two surveys which have recently been carried out in France (reactions to urban road pricing and perception of electric vehicles). It describes the benefits of this experimental approach which allows stated behaviours to be checked to a considerable degree. The limits and potential developments of this survey technique are also discussed.     

基于意向调查数据的非集计模型研究

当交通系统中引入新的交通方式时,传统的基于实绩选择调查数据的交通需求预测方法对于方式分担预测将会无效。本文以新交通方式的分担率预测模型为研究对象,提出基于实绩选择调查和假设意向调查组合数据的非集计模型,对模型中各种交通方式的效用函数进行了深入研究,并以东直门至首都机场的轨道交通客流预测为例,进行了参数估计和轨道分担率预测。实例研究表明,模型能够较准确的预测出新交通方式的分担率。