Trip chaining is a growing phenomenon in travel and activity behaviour. Individuals increasingly seek out opportunities to minimise the amount of travel required as part of activity fulfilment, given the competing demands on time budgets and their valuation of travel time savings. This search for ways of fulfilling (more) activities with less travel input has produced a number of responses, one of which is trip chaining. A particularly important policy implication of trip chaining is the potential barrier it creates in attracting car users to switch to public transport. This paper seeks to improve our understanding of trip chaining as a barrier to public transport use. A series of discrete choice models are estimated to identify the role that socio-economic and demographic characteristics of households have on the propensity to undertake trip chains of varying degrees of simplicity/complexity that involve use of the car or public transport with an embedded commuting or non-commuting primary purpose. Multinomial logit, nested logit and random parameter logit models are developed and contrasted to establish the gains in relaxing the strict conditions of the multinomial logit model. 相似文献
This paper presents a newly developed decision support model to assess transport infrastructure projects: CBA-DK. The model combines use of conventional cost–benefit analysis to produce aggregated single point estimates, with quantitative risk analysis using Monte Carlo simulation to produce interval results. The embedded uncertainties within traditional CBA such as ex-ante based investment costs and travel time savings are of particular concern. The paper investigates these two impacts in terms of the Optimism Bias principle which is used to take account of the underestimation of construction costs and the overestimation of travel time savings. The CBA-DK methodological approach has been used to apply suitable probability distribution functions on the uncertain parameters, thus resulting in feasibility risk assessment moving from point to interval results. The proposed assessment model makes use of both deterministic and stochastic based information. Decision support as illustrated in this paper aims to provide assistance in the development and ultimately the choice of action, while accounting for the uncertainties surrounding transport appraisal schemes. The modelling framework is illustrated by the use of a case study appraising airport and runway alternatives in the capital of Greenland – Nuuk. The case study has been conducted in cooperation with the Home Rule Authorities of Greenland. 相似文献
There has been a great deal of research on deriving estimates of the value of travel time savings (VTTS) as a way of converting
travel time benefits of toll roads relative to free routes into monetary units, the major user benefit in the development
of forecasts of traffic and hence revenue streams. By contrast there has been almost no consideration given to identifying
the role that various tollroad products play in establishing preferences for toll routes over non-tolled routes. Increasingly
tollroads give users the option to pay by cash at a toll booth, by electronic tolling or by a pre- or post-paid debit and
credit account system involving vehicle identification. The efficiency gained by electronic tolling for both the users and
the operator have resulted in moves in many jurisdictions to eliminate cash collection entirely (or not introduce it when
introducing a new tolled road facility), and to introduce a range of pre- and post-payment options. This has been accompanied
by a growing move to distance-based charging in some contexts which is more cumbersome to structure with a cash option. This
paper investigates current and potential travellers’ preferences for a range of toll products and how much individual’s are
willing to pay for very specific toll products. Data from a stated choice experiment is used in a mixed logit model to establish
the role that toll products play in the context of offered times and costs of alternative routes, in choosing between alternative
ways of paying for the use of tolled routes.
John M. RoseEmail:
David A. Hensher
is Professor of Management, and Founding Director of the Institute of Transport and Logistics Studies. David is a Fellow of
the Academy of Social Sciences in Australia, Recipient of the 2006 Engineers Australia Transport Medal for lifelong contribution
to transportation, member of Singapore Land Transport Authority International Advisory Panel (Chaired by Minister of Transport).
David is on the editorial boards of 10 of the leading transport journals and Area Editor of Transport Reviews. David was appointed
in 1999 by one of the worlds most prestigious academic publishing houses—Elsevier Science press as series and volume editor
of a new handbook series “Handbooks in Transport”. Appointments over recent years include: a member of the executive committee
that reviewed bus transport bids for the Olympic Games, the NSW Government’s Peer Review Committee for the Sydney Strategic
Transport Plan, Peer reviewer for Transfund (NZ) of the New Zealand project evaluation program, Peer reviewer of the NZ Land
Passenger Transport Procurement Strategy for Land Transport NZ, member of the executive committee of ATEC, a consortium promoting
a freight rail system between Melbourne and Darwin; economic adviser to Gilbert+Tobin Lawyers on valuation methods in IP context;
panel member of NSW Ministry of Transport benchmarking program; specialist toll road project adviser to Thiess.
John M. Rose
is Director of the Industry Program and a Deputy Director at Institute of Transport and Logistics Studies (ITLS). John’s research
interests are in the areas of discrete choice modelling and efficient stated choice experiments. John has several articles
published in the top Transportation and Logistics journals (including Transportation, Transportation Research A, B and E)
and is a co-author of (with Professors David Hensher and William Greene) Applied Choice Analysis; A Primer, (2005) by Cambridge
University Press. He is currently writing a book on generating efficient stated choice experimental designs (with Mike Bliemer,
Delft). 相似文献
Researchers have improved travel demand forecasting methods in recent decades but invested relatively little to understand their accuracy. A major barrier has been the lack of necessary data. We compiled the largest known database of traffic forecast accuracy, composed of forecast traffic, post-opening counts and project attributes for 1291 road projects in the United States and Europe. We compared measured versus forecast traffic and identified the factors associated with accuracy. We found measured traffic is on average 6% lower than forecast volumes, with a mean absolute deviation of 17% from the forecast. Higher volume roads, higher functional classes, shorter time spans, and the use of travel models all improved accuracy. Unemployment rates also affected accuracy—traffic would be 1% greater than forecast on average, rather than 6% lower, if we adjust for higher unemployment during the post-recession years (2008 to 2014). Forecast accuracy was not consistent over time: more recent forecasts were more accurate, and the mean deviation changed direction. Traffic on projects that opened from the 1980s through early 2000s was higher on average than forecast, while traffic on more recent projects was lower on average than forecast. This research provides insight into the degree of confidence that planners and policy makers can expect from traffic forecasts and suggests that we should view forecasts as a range of possible outcomes rather than a single expected outcome.
ABSTRACT The built environment (BE) is widely accepted to influence transit use (TU). Evidence to date suggests the relationship is dependent on many factors which can be difficult to account for in quantitative studies. This creates barriers to transferring research into practice. Considering many studies together can be useful for accounting for more of the factors impacting transit use. Yet, meta-analysis of research measuring these influences was last undertaken in 2010 based on 18 studies. Since then 90 new quantitative studies have been published. These recent studies use improved methodologies and are conducted in more diverse geographies. This paper reports an improved and updated meta-analysis of built environment impacts on transit use. It compares elasticity estimates from research published pre-and post-2010 and explores the impact of new methods and a more diverse geographical representation on findings. Updated meta-elasticities range from <0.01 to 0.26; a similar range to the 2010 study. However, at the individual indicator levels, more recent results are different. Elasticities for urban density, including population, employment and commercial density, have increased significantly in studies published since 2010, as did that of land use mix. However, measures of local access, design and jobs-housing balance decreased in post-2010 studies. These results confirm the small but imprecise relationship between the BE and TU. Results also suggest that while the range of elasticity impacts is relatively consistent, new study methodologies, notably those that control for regional accessibility and self-selection, and the increasing geographical diversity in study applications, is acting to change BE-TU findings at the indicator level. Research setting and context are important to consider when using empirical results to design BE strategies to promote transit use. 相似文献
This study measures severity of network disruptions in the Minneapolis–St. Paul region by comparing the cumulative opportunity accessibility before-and-after removing freeway segments. Accessibility to jobs and accessibility to resident workers are measured respectively in the morning and evening peak hours. It is shown that the links with more severe consequences of disruption tend to be near or at freeway interchanges. Betweenness helps explain risk severity. 相似文献
Transportation - Mobility as a Service (MaaS) is the integrated and on-demand offering of new mode-sharing transport schemes, such as ride-share, car-share or car-pooling. MaaS schemes may solve... 相似文献