E-bikes among older adults: benefits,disadvantages, usage and crash characteristics

Transportation - The promotion of sustainable and healthy mobility among older adults (≥?65 years) is an important challenge. E-bikes may be part of the solution, but research...     

Wanting to travel,more or less: Exploring the determinants of the deficit and surfeit of personal travel

This study investigates the determinants of peoples desire to increase or decrease the amount of travel they do. We use data from 1,357 working commuters, residents of three different neighborhoods in the San Francisco Bay Area, California. The dependent variables are indicators of Relative Desired Mobility for ten categories of travel (short- and long-distance overall and by several mode- and purpose-specific categories). These variables are measured on a five-point ordinal scale ranging from much less to much more, through which the respondents indicated the amount of travel they want to do (in the category in question) compared to what they are doing now. Censored ordered probit models were developed for these variables, with explanatory variables including general travel attitudes, specific liking for travel in each of the same separate categories, objective and subjective measures of the amount currently traveled in each category, and personality, lifestyle, and socio-demographic characteristics. The results support the hypotheses that the liking for travel has a strong positive impact, and subjective qualitative assessments of mobility have a strong negative impact, on the desire to increase ones travel. Finally, a number of general types of effects on Relative Desired Mobility were identified, among them complementarity and substitution effects. The results of this study can provide policy makers and researchers with new and valuable insight into key principles that affect individual travel demand.     

Application of perceived value model to identify factors affecting passengers' repurchase intentions on city bus: A case of the Taipei metropolitan area

This paper establishes and tests the perceived value model, which is applied to identify the factors affecting the passengers' repurchase intentions on city bus. In this study, perceived value is a trade-off between perceived benefits and perceived costs. And the main part of perceived benefits is service quality. We (1) measured service quality using a multiple-items scale, (2) integrated perceived non-monetary price as a part of perceived costs, and (3) simultaneously incorporated the attractiveness of alternative modes. Data was collected via a questionnaire survey in the Taipei metropolitan area and the model was tested using path analysis performed by LISREL. The results indicate that all causal relationships are statistical significant. Finally, this study concludes by discussing managerial implications and making suggestions for future research.     

Intra-destination travel behavior of alpine tourists: a literature review on choice determinants and the survey work

Transportation - In the face of a continuous increase in the number of tourists in the Alps, the associated traffic volumes, and the resulting negative externalities, there is an urgent need to...     

Estimating the robustness of questionnaire results: lessons from a mixed-mode survey of expectations for tele-working and road-based business travel

The robustness of questionnaire results to various forms of bias are explored in the context of a dual-mode (web and hardcopy) survey of employers’ anticipations of levels of employee commuting and business travel activity under a range of future ICT scenarios. The questionnaire incorporated several innovative features which, together with the dual-mode format, allowed an unusually wide range of analyses. For example: the robustness of respondents’ opinions was tested by examining the effect of incorporating alternative versions of a briefing text, one being very positive and one very negative, about the role of ICT; instrument bias was identified via detailed comparison of the results from the two versions of the questionnaire; and the impact of exogenous factors which are often ignored or taken as constant was assessed via special supplementary questions. Analysis showed that the robustness of opinions and expectations varied and was influenced by respondent characteristics, and that results from the two versions of the questionnaire differed significantly. It is concluded that opinions and expectations are less robust, and questionnaire results are more subject to bias and myopic interpretation, than is generally recognised and that web-based surveys seem particularly vulnerable to sampling bias. Methods are suggested for measuring robustness, for reducing bias and for validating and contextualising results. The use of contrasting briefing texts is recommended as a means of establishing the robustness of opinions and expectations while supplementary questions are recommended for validating and contextualising SP and SE exercises.

Acceptance of disincentives to driving and pro-environmental transport intentions: the role of value structure,environmental beliefs and norm activation

Transportation - In order to facilitate pro-environmental transport mode use it is important to promote acceptance for disincentives to driving and intentions to use public transport. The present...     

The role of attitude structures,direct experience and reframing for the success of congestion pricing

Congestion pricing was introduced in Stockholm in 2006, first as a trial followed by a referendum, and permanently from 2007. Public attitudes to the charges became more negative during the period from the decision to the start of the system. Once the trial started, public attitudes became dramatically more positive over the following years, going from 2/3 against the charges to more than 2/3 in favor of the charges. Self-reported changes in behavior and attitudes considerably underestimate actual changes: about 3/4 of the decrease in car trips and more than half of the change in attitudes seem to have gone unnoticed by respondents, ex post. Self-interest and belief in the charges’ effectiveness strongly affect attitudes at any given point in time, but can only explain a minor part of the change in attitudes. I suggest that the debate and the shift in attitudes can be understood as a public and political reframing of the congestion charges over time.     

Telecommuting and travel: state of the practice,state of the art

This paper provides an overview of the status of telecommuting in the United States, especially as it relates to changes in travel behavior. Regarding the state of the practice, the paper discusses some refinements to the definition of telecommuting that have developed through increased operational experience. It reports several policy statements involving telecommuting, and explores the appeal of telecommuting as a public policy instrument. It highlights some trends in the implementation of home-based and work center-based telecommuting, and suggests that visible public-sector involvement has been crucial to the increased activity in this area.In sketching the state of the art, the paper outlines some frequently-stated hypotheses on telecommuting and travel behavior, and summarizes current empirical findings relating to those hypotheses. Finally, it suggests a variety of topics suitable for further research. These include studying factors influencing the ultimate adoption levels of telecommuting; impacts on energy/air quality, mode choice, and location/urban form; interactions with other transportation demand management strategies; relationships to the traditional urban travel demand forecasting process; cost/benefit tradeoffs; and telecommuting centers.     

Correction to: The role of travel demand and network centrality on the connectivity and resilience of an urban street system

Transportation - In the original publication of the article, the first, second and fourth authors’ affiliations are published incorrectly.     

The role of perceived environment,neighbourhood characteristics,and attitudes in walking behaviour: evidence from a rapidly developing city in China

Transportation - The associations between objective and subjective dimensions of the built environment and walking behaviour have been examined extensively in existing studies. However, the...     

Evolution of the household vehicle fleet: Anticipating fleet composition, PHEV adoption and GHG emissions in Austin, Texas

In today’s world of volatile fuel prices and climate concerns, there is little study on the relationship between vehicle ownership patterns and attitudes toward vehicle cost (including fuel prices and feebates) and vehicle technologies. This work provides new data on ownership decisions and owner preferences under various scenarios, coupled with calibrated models to microsimulate Austin’s personal-fleet evolution.Opinion survey results suggest that most Austinites (63%, population-corrected share) support a feebate policy to favor more fuel efficient vehicles. Top purchase criteria are price, type/class, and fuel economy. Most (56%) respondents also indicated that they would consider purchasing a Plug-in Hybrid Electric Vehicle (PHEV) if it were to cost $6000 more than its conventional, gasoline-powered counterpart. And many respond strongly to signals on the external (health and climate) costs of a vehicle’s emissions, more strongly than they respond to information on fuel cost savings.Twenty five-year simulations of Austin’s household vehicle fleet suggest that, under all scenarios modeled, Austin’s vehicle usage levels (measured in total vehicle miles traveled or VMT) are predicted to increase overall, along with average vehicle ownership levels (both per household and per capita). Under a feebate, HEVs, PHEVs and Smart Cars are estimated to represent 25% of the fleet’s VMT by simulation year 25; this scenario is predicted to raise total regional VMT slightly (just 2.32%, by simulation year 25), relative to the trend scenario, while reducing CO₂ emissions only slightly (by 5.62%, relative to trend). Doubling the trend-case gas price to $5/gallon is simulated to reduce the year-25 vehicle use levels by 24% and CO₂ emissions by 30% (relative to trend).Two- and three-vehicle households are simulated to be the highest adopters of HEVs and PHEVs across all scenarios. The combined share of vans, pickup trucks, sport utility vehicles (SUVs), and cross-over utility vehicles (CUVs) is lowest under the feebate scenario, at 35% (versus 47% in Austin’s current household fleet). Feebate-policy receipts are forecasted to exceed rebates in each simulation year.In the longer term, gas price dynamics, tax incentives, feebates and purchase prices along with new technologies, government-industry partnerships, and more accurate information on range and recharging times (which increase customer confidence in EV technologies) should have added effects on energy dependence and greenhouse gas emissions.     

TTB or not TTB, that is the question: a review and analysis of the empirical literature on travel time (and money) budgets

This paper summarizes and analyses findings from more than two dozen aggregate and disaggregate studies of travel time (and sometimes money) expenditures, exploring the question of the existence of a constant travel time budget. We conclude (with prior researchers) that travel time expenditures are not constant except, perhaps, at the most aggregate level. Nevertheless, individuals’ travel time expenditures do show patterns that can be partly explained by measurable characteristics. Travel time expenditure is strongly related to individual and household characteristics (e.g., income level, gender, employment status, and car ownership), attributes of activities at the destination (e.g., activity group and activity duration), and characteristics of residential areas (e.g., density, spatial structure, and level of service). To the extent that travel time expenditures are constant at the aggregate level, the underlying mechanisms explaining that regularity are not well understood. Consequently, further research into explaining travel time and money expenditure patterns is justified.     

Determinants of bicycle commuting in the Washington,DC region: The role of bicycle parking,cyclist showers,and free car parking at work

This article examines the role of bicycle parking, cyclist showers, free car parking and transit benefits as determinants of cycling to work. The analysis is based on commute data of workers in the Washington, DC area. Results of rare events logistic regressions indicate that bicycle parking and cyclist showers are related to higher levels of bicycle commuting—even when controlling for other explanatory variables. The odds for cycling to work are greater for employees with access to both cyclist showers and bike parking at work compared to those with just bike parking, but no showers at work. Free car parking at work is associated with 70% smaller odds for bike commuting. Employer provided transit commuter benefits appear to be unrelated to bike commuting. Regression coefficients for control variables have expected signs, but not all are statistically significant.     

The role of cities in achieving the EU targets on biofuels for transportation: The cases of Berlin,London, Milan and Helsinki

Road transportation is a strongly growing source of CO₂, and use of biofuels represents one option to reduce end-of-pipe emissions of the existing car fleet. In this contribution, the implementation of the EU Biofuels Directive (2003/30/EC) and related voluntary measures at the local level are examined in Germany, UK, Italy and Finland and the cities of Berlin, London, Milan and Helsinki. Even though they are not directly involved in the implementation of the biofuel directive, all four cities studied have played an important role in emissions reduction by voluntarily participating in research and demonstration projects and by using biofuels in their own fleet. An analysis of the numerous causes and driving forces leading to different local level measures is provided. The environmental sensitivity, usually examined at national level, and the national level implementation of the EU Biofuels Directive (2003/30/EC) were not directly correlated with the city-level activities Instead, support from local businesses and acquisition of EU funds were considered to be valid explanatory factors for the city-level activities. In addition, through horizontal networking cities are starting to exchange know-how gained in their projects, contributing in this way to the accumulation of experience for future policies and technologies.     

Incentive measures to avoid the illegal parking of dockless shared bikes: the relationships among incentive forms,intensity and policy compliance

Transportation - The recent development of shared-bike systems in China has brought convenience for users, as well as great pressure on bicycle parking management. There is limited empirical...