Internet mobility survey sampling biases in measuring frequency of use of transport modes

We develop a quantitative analysis of the biases that arise when measuring trip frequencies for a general population through an online survey instrument. Data from a national official survey in Italy, concerning both mobility behaviors and skills in using computers and internet, have been deployed to assess differences in mobility levels between those that can answer a computer/internet survey and those that cannot. Positive correlations were found between ability in using ICT tools and trip frequencies. These latter are about 15% to 150% higher for the "ICT literate", according to the travel means under consideration. A Heckman sample selection model showed us that these biases have different explanations. People knowing how to use internet are different from the others in they car driving behavior due to a range of self-related factors. Conversely, public transport patterns of use are more similar between the two groups: the observed bias is mainly due to the fact of using internet in itself, which could for example lead to a more active lifestyle. Such distinction is of practical interest because it can help defining a method to correct these biases. According to our results, the overestimation of public transport frequency of use of an internet survey could be corrected by looking at the internet diffusion in the population. On the contrary, corrections for car driving frequencies are more complex and should be based on differences in attitudinal and personal characteristics between internet survey respondents and the remainder of the populatio

SaferDrive: an NLG-based Behaviour Change Support System for Drivers

Despite the long history of Natural Language Generation (NLG) research, the potential for influencing real world behaviour through automatically generated texts has not received much attention. In this paper, we present SaferDrive, a behaviour change support system that uses NLG and telematic data in order to create weekly textual feedback for automobile drivers, which is delivered through a smartphone application. Usage-based car insurances use sensors to track driver behaviour. Although the data collected by such insurances could provide detailed feedback about the driving style, they are typically withheld from the driver and used only to calculate insurance premiums. SaferDrive instead provides detailed textual feedback about the driving style, with the intent to help drivers improve their driving habits. We evaluate the system with real drivers and report that the textual feedback generated by our system does have a positive influence on driving habits, especially with regard to speeding

Estimating direct rebound effects for personal automotive travel in Great Britain

Direct rebound effects result from increased consumption of cheaper energy services. For example, more fuel-efficient cars encourage more car travel. This study is the first to quantify this effect for personal automotive travel in Great Britain. We use aggregate time-series data on transport activity, fuel consumption and other relevant variables over the period 1970-2011 and estimate the direct rebound effect from the elasticity of vehicle kilometres with respect to: a) vehicle fuel efficiency (km/MJ); b) the fuel cost of driving (£/km); and c) road fuel prices (£/MJ). We estimate a total of 54 models, paying careful attention to methodological issues and model diagnostics. Taking changes in fuel efficiency as the explanatory variable, we find no evidence of a long-run direct rebound effect in Great Britain over this period. However, taking changes in either the fuel cost of driving or fuel prices as the explanatory variable we estimate a direct rebound effect in the range 10% to 27% with a mean of 18%. This estimate is consistent with the results of US studies and suggests that one fifth of the potential fuel savings from improved car fuel efficiency may have been eroded through increased driving. We also show how the normalisation of distance travelled (per capita, per adult or per driver) affects the results obtained

Is Beer Healthier than Booze? How the Change in Consumption Shares of Alcoholic Beverage Types Affects Mortality in Young People

This paper uses cross-state and cross-regional variation in both levels and growth rates of the shares of alcohol beverage types to ascertain the effect, if any of this variation on health outcomes related to excessive alcohol consumption, with particular focus on beer versus spirits (“hard liquor”). Some evidence is found that beer drinking is more negative for traffic fatalities and suicides for ages 15-19, but results are not conclusive. Income is a strong predictor of lower mortality.

The Intersection of Urban Form and Mileage Fees: Findings from the Oregon Road User Fee Pilot Program, Research Report 10-04

This report analyzes data from the 2006-2007 Oregon Road User Fee Pilot program to assess if and how urban form variables correlate with travel behavior changes that participants made in response to the mileage-based fee program. It finds that charging a noticeably higher fee for driving in congested conditions can successfully motivate households to reduce their VMT in those times and places where congestion is most a problem. Households in both traditional (mixed use, dense, transit-accessible) and suburban (single-use, low density) neighborhoods will likely reduce their peak-hour and overall travel under a charging scheme that charges a high-rate for peak-hour travel, though households in the traditional neighborhoods will do so more. It also finds that a mileage fee program that charges a high rate during the peak hour is likely to strengthen the underlying influence of urban form on travel behavior. In other words, land use probably will matter more to transportation planning if the nation shifts to a new paradigm of mileage-based financing and pricing system. For transportation policy-makers, this raises another layer of consideration when designing the optimal rate structure to achieve policy goals—either reduced VMT and congestion or sustained funding sources. For urban planners, this offers a wonderful opportunity to move towards a sustainable built environment through revised and compatible land use regulation under the context of a mileage-based fee. The research also reveals that program design could significantly affect a household’s response to a mileage-based fee program. Particularly in Portland, the establishment of an endowment account for participants actually increased household VMT when a flat-rate fee was charged, the opposite to policy-makers’ expectation. One possible explanation is that paying the mileage-based fees once a month, instead of paying the gas tax at each visit to the pump, may have encouraged households to drive more due to the reduced gas price at the pump