Brian H Y Lee

Better Understanding of Factors Influencing Likelihood of Using Shared Bicycle Systems and Frequency of Use

Planning and transportation professionals are promoting a variety of sustainable travel alternatives, such as public transit usage, walking, and cycling, as affordable transportation options to counter the negative effects of widespread car use. In their traditional form, these alternative transport modes do not always offer the flexibility or convenience of the car; therefore, innovative solutions have been developed to allow active and public transport to compete better with the car. Shared bicycle systems have been adopted by a growing number of cities and regions throughout the world, yet little is known about the users of the systems and their motivations. A survey was conducted in Montreal, Quebec, Canada, in the summer of 2010 to determine the factors that encouraged individuals to use the system and the elements that influenced frequency of use. The factor found to have the greatest effect on the likelihood for use of a shared bicycle system was the proximity of home to docking stations. Ownership of a yearly shared bicycle membership was associated with cyclists riding shared bicycles 15 additional times per year. Respondents indicated that they valued the shared bicycles trendy status and the role that it could play in bicycle theft prevention. The potential of shared bicycle systems can be maximized by increasing the number of docking stations in residential neighborhoods and by emphasizing the popularity of shared bicycles and theft prevention in advertising campaigns.

Reexamining the Influence of Work and Nonwork Accessibility on Residential Location Choices with a Microanalytic Framework

The concept of accessibility has long been theorized as a principal determinant of residential choice behavior. Research on this influence is extensive but the empirical results have been mixed, with some research suggesting that accessibility is becoming a relatively insignificant influence on housing choices. Further, the measurement of accessibility must contend with complications arising from the increasing prevalence of trip chains, nonwork activities, and multiworker households, and also reconcile person-specific travel needs with household residential decisions. With this paper we contribute to the literature by addressing the gap framed by these issues and present a novel residential choice model with three main elements of innovation. First, we operationalize a time–space prism (TSP) accessibility measure, which we believe to be the first application of its kind in a residential choice model. Second, we represent the choice sets in a building-level framework—the lowest level of spatial disaggregation available for modeling residential choices. Third, we explicitly examine the influence of nonwork accessibility at both the local and the person level. This residential choice model is applied in the central Puget Sound region using a 2006 household activity survey. The model estimation results confirm that accessibility remains an important influence, with individual-specific work accessibility as the most critical consideration. By using the TSP approach we establish that nonwork accessibility in a trip-chaining context does contribute to the residential choice decision, even after accounting for work accessibility. Empirical tests also reveal a useful aggregation method to incorporate individual-specific accessibility measures into a household-level choice model.

Event-Based Framework for Noncompliant Driver Behavior at Single-Lane Roundabouts

Roundabouts are an emerging form of intersection control in the United States. The nature of roundabouts, requiring drivers to yield at entry, promotes a level of road user responsibility higher than that at inter sections with other types of control. This research addresses current roundabout modeling and analysis methods by focusing on the types of driver behavior that are not gap acceptance–based, do not follow the offside priority rule, are interactive between traffic streams, and have unique effects on roundabout performance. A new framework for describing priority-taking, priority-abstaining, and priority-surrendering behavior at roundabouts is presented; a reduction methodology for the extraction of these types of behavior from video is described. The findings suggest that these noncompliant driver behaviors are, prevalent, may significantly affect roundabout performance, and remain unaccounted for in current modeling approaches. Furthermore, the results indicate that frequency of priority-taking behavior remains constant, whereas priority-abstaining behavior diminishes with time since construction of a roundabout.

Traveler Perspectives of Greenway Quality in Northern New England

Greenways across a range of landscapes from urban to natural serve society as both transportation corridors and recreational pathways. Because of these dual functions, planning and management of greenways warrant an interdisciplinary approach that incorporates frameworks from the fields of transportation and outdoor recreation. Research was conducted to (a) investigate the relationship between transportation and recreation from a greenway users perspective, (b) consider and integrate transportation and recreation frameworks that measure quality of greenway travel, and (c) determine the significance of settings in user perceptions of quality. On-site surveys of users (n = 841) across three greenways in northern New England were administered to learn how travelers used and perceived the quality of these facilities. Findings showed that greenways were used primarily for recreation but often incorporated varying elements of transportation. Furthermore, traveler perceptions of quality differed across settings. Transportation and recreation planning frameworks can be integrated to provide a more holistic approach to greenway planning and management.

Allocation of Intrahousehold Motorized Vehicles: Exploration with the 2009 National Household Travel Survey

This study examines allocation of intrahousehold vehicles to drivers and trips by using data from the 2009 National Household Travel Survey and is motivated by the knowledge that reallocating household vehicles is a reasonable short-term action to reduce fuel and associated emissions. Models are developed for households in the national sample and for segmentations by population and census regions. Binomial logistic regression is used to model whether a household fleet is optimal and is a high-potential saver (HPS). Of households with two or more vehicles, 31% are classified as HPS. Linear regression is used to model the number of gallons of fuel a household can potentially save per year with vehicle reallocation. About 59% of households can reduce fuel consumption by an estimated 5.2%, or approximately 5 billion gallons of fuel nationally, if they reallocate their fleet. Household size and life-cycle, travel behavior, and fleet composition are related to allocation of intrahousehold vehicles. Similar variables are significant predictors of potential gallons of savings and whether a household is an HPS. Models are consistent across regions with minor exceptions. Rural areas had differences from more urban areas. This study has demonstrated that appreciable savings in fuel consumption and associated emissions are plausible through vehicle reallocation, and the ability to pursue this countermeasure in the short-term motivates further research to provide fuller understanding of the causal mechanisms and target households for intervention.

Intercity Passenger Rail in the Context of Dynamic Travel Markets

This report develops an analytical framework or structural plan to improve understanding of how current or potential intercity travelers make the choice to travel by rail. This framework provides guidance for use by practitioners and decision makers considering alternative planning, operating, financing, service, and capital investment strategies for intercity passenger rail service in existing and potential travel markets; and it allows users to evaluate how mode choice is affected by a variety of changing and evolving parameters. The framework developed through this research is based on an examination of fundamental values, preferences, and attitudes affecting travel mode choice. Identification of relevant parameters extracted from this analysis served as input to a comprehensive survey used to gather necessary data for developing an Integrated Choice/Latent Variable (ICLV) forecasting model. Building directly on the results calculated in this forecasting model is the scenario testing tool, a series of interconnected spreadsheets which make available to the analyst a wide variety of data and procedures needed in the application of quick-turn-around scenario testing. Together, the ICLV forecasting model and scenario testing tool provide a sophisticated framework for analyzing intercity travel behavior.

Mobility, Communication, and Place: Navigating the Landscapes of Suburban U.S. Teens

In the context of sprawl and car dependence in U.S. metropolitan areas, young people—especially teens in middle-class suburbs—create new mobility practices with near-universal adoption of cellphones and high levels of access to automobiles. The growth in the use of handheld mobile devices for communication and information might enhance independent mobility and accessibility for higher socioeconomic segments of the youth population. In a project with teens in two high schools near Burlington, Vermont, representing somewhat different land-use contexts, we examined how often and in what ways teens use information and communication technologies (ICTs) to arrange transportation, what travel needs are being met and which transportation modes are used, and how household situations contextualize the use of ICTs for mobility. We explore the ways in which access to cellphones and cars affects how high school teens organize and enact their daily lives in suburban and rural contexts. We employ a conceptual framework that connects mobility, communication, and place based on the notion that contemporary teens generate new intersections among the built, digital, and social landscapes.

Assessing the Relative Crash Fault of Out-of-State Drivers in Vermont, USA

This study examined single- and two-vehicle police-reported crashes in Vermont, United States, between 2003 and 2008. It evaluated the likelihood of being at-fault for Vermont drivers versus out-of-state drivers older than age 25 years. Analysis using logistic regression estimated that out-of-state drivers are twice as likely to be at-fault for a single-vehicle crash and 7% more likely to be at-fault for a two-vehicle crash. Season of year and road type (paved vs. unpaved) were statistically significant interactions for Vermont and out-of-state drivers for single-vehicle crashes. Driving during the winter months had more pronounced effects of increasing single-vehicle crash fault for out-of-state drivers than for Vermont drivers. No statistically significant differences were found in the factors that affect crash fault between Vermont and out-of-state drivers for two-vehicle crashes. The relative evaluation of crash fault for nonlocal drivers has been understudied in the United States. Previous research, conducted mostly in other countries, has been limited but has shown that foreign drivers are more likely to be involved in a crash. This study suggests the need for further study of drivers away from home within their own country as well as identification of associated interventions.

Modeling the Effects of an Urban Growth Boundary on Vehicle Travel in a Small Metropolitan Area

An integrated land-use–transportation model was used to simulate the impact that an urban growth boundary would have on vehicle miles of travel in a small metropolitan community over a forty-year modeling horizon. The results of the modeling effort indicate that even in an area with low to moderate population growth, there is the potential to reduce vehicle miles of travel per person by as much as 25% from a business-as-usual scenario over a forty-year period. The reduction would result primarily from a shift of driving alone to carpooling or walking for many trips. A scenario in which growth is concentrated in a single urban core would also benefit from shorter average trip lengths; a scenario with multiple village centers would not have shorter trip lengths, but would still have significant improvements in total vehicle miles of travel.

Composition of Vehicle Occupancy for Journey-to-Work Trips: Evidence of Ridesharing from 2009 National Household Travel Survey Vermont Add-On Sample

Ridesharing serves to mitigate pollution and congestion with minimal investment of public capital while also increasing the efficiency of the transportation system. This research addresses the gaps in the literature on the structure and formation of ridesharing by identifying individual, household, and physical-environment characteristics that correspond with an individuals choice to rideshare instead of drive alone. For a fuller understanding of ridesharing behavior, there first must be a better understanding of who is in the vehicle, not just how many. A distinction is made between intrahousehold (internal) and interhousehold (external) ridesharing. With the Vermont add-on sample of the 2009 National Household Travel Survey, a multinomial logit model and nested logit model were developed to examine the determinants of ridesharing. The analysis in this research stresses the importance of the way ridesharing behavior is extracted from survey data. Further, a new method for calculating household vehicle availability is presented; the method places less importance on drivers who are not full-time workers. Results indicate that employment density, longer distance traveled to work, and working in a small urban area have positive influences on the likelihood of ridesharing. Higher vehicle availability in the household, age, sex (male), and a longer time spent per trip on the journey to work were all found to influence the propensity to rideshare negatively. Cost of travel does not significantly affect ridesharing.