Problem: Localities and states are turning to land planning and urban design for help in reducing automobile use and related social and environmental costs. The effects of such strategies on travel demand have not been generalized in recent years from the multitude of available studies. Purpose: We conducted a meta-analysis of the built environment-travel literature existing at the end of 2009 in order to draw generalizable conclusions for practice. We aimed to quantify effect sizes, update earlier work, include additional outcome measures, and address the methodological issue of self-selection. Methods: We computed elasticities for individual studies and pooled them to produce weighted averages. Results and conclusions: Travel variables are generally inelastic with respect to change in measures of the built environment. Of the environmental variables considered here, none has a weighted average travel elasticity of absolute magnitude greater than 0.39, and most are much less. Still, the combined effect o...

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Travel and the Built Environment

The built environment is thought to influence travel demand along three principal dimensions —density, diversity, and design. This paper tests this proposition by examining how the ‘3Ds’ affect trip rates and mode choice of residents in the San Francisco Bay Area. Using 1990 travel diary data and land-use records obtained from the U.S. census, regional inventories, and field surveys, models are estimated that relate features of the built environment to variations in vehicle miles traveled per household and mode choice, mainly for non-work trips. Factor analysis is used to linearly combine variables into the density and design dimensions of the built environment. The research finds that density, land-use diversity, and pedestrian-oriented designs generally reduce trip rates and encourage non-auto travel in statistically significant ways, though their influences appear to be fairly marginal. Elasticities between variables and factors that capture the 3Ds and various measures of travel demand are generally in the 0.06 to 0.18 range, expressed in absolute terms. Compact development was found to exert the strongest influence on personal business trips. Within-neighborhood retail shops, on the other hand, were most strongly associated with mode choice for work trips. And while a factor capturing ‘walking quality’ was only moderately related to mode choice for non-work trips, those living in neighborhoods with grid-iron street designs and restricted commercial parking were nonetheless found to average significantly less vehicle miles of travel and rely less on single-occupant vehicles for non-work trips. Overall, this research shows that the elasticities between each dimension of the built environment and travel demand are modest to moderate, though certainly not inconsequential. Thus it supports the contention of new urbanists and others that creating more compact, diverse, and pedestrian-orientated neighborhoods, in combination, can meaningfully influence how Americans travel.

Travel demand and the 3ds: density, diversity, and design

Research in transportation, urban design, and planning has examined associations between physical environment variables and individuals' walking and cycling for transport. Constructs, methods, and findings from these fields can be applied by physical activity and health researchers to improve understanding of environmental influences on physical activity. In this review, neighborhood environment characteristics proposed to be relevant to walking/cycling for transport are defined, including population density, connectivity, and land use mix. Neighborhood comparison and correlational studies with nonmotorized transport outcomes are considered, with evidence suggesting that residents from communities with higher density, greater connectivity, and more land use mix report higher rates of walking/cycling for utilitarian purposes than low-density, poorly connected, and single land use neighborhoods. Environmental variables appear to add to variance accounted for beyond sociodemographic predictors of walking/cycling for transport. Implications of the transportation literature for physical activity and related research are outlined. Future research directions are detailed for physical activity research to further examine the impact of neighborhood and other physical environment factors on physical activity and the potential interactive effects of psychosocial and environmental variables. The transportation, urban design, and planning literatures provide a valuable starting point for multidisciplinary research on environmental contributions to physical activity levels in the population.

Environmental correlates of walking and cycling: Findings from the transportation, urban design, and planning literatures

How the built environment affects physical activity: views from urban planning

The potential to moderate travel demand through changes in the built environment is the subject of more than 50 recent empirical studies. The majority of recent studies are summarized. Elasticities of travel demand with respect to density, diversity, design, and regional accessibility are then derived from selected studies. These elasticity values may be useful in travel forecasting and sketch planning and have already been incorporated into one sketch planning tool, the Environmental Protection Agency's Smart Growth Index model. In weighing the evidence, what can be said, with a degree of certainty, about the effects of built environments on key transportation "outcome" variables: trip frequency, trip length, mode choice, and composite measures of travel demand, vehicle miles traveled (VMT) and vehicle hours traveled (VHT)? Trip frequencies have attracted considerable academic interest of late. They appear to be primarily a function of socioeconomic characteristics of travelers and secondarily a function...

http://m.santa-clarita.com/vceir/Draft%20EIR/Volume%203/Apx_4_3i_Travel_Built_Environment.pdf

Travel and the built environment: a synthesis

This study examined the effects of land use and attitudinal characteristics on travel behavior for five diverse San Francisco Bay Area neighborhoods. First, socio-economic and neighborhood characteristics were regressed against number and proportion of trips by various modes. The best models for each measure of travel behavior confirmed that neighborhood characteristics add significant explanatory power when socio-economic differences are controlled for. Specifically, measures of residential density, public transit accessibility, mixed land use, and the presence of sidewalks are significantly associated with trip generation by mode and modal split. Second, 39 attitude statements relating to urban life were factor analyzed into eight factors: pro-environment, pro-transit, suburbanite, automotive mobility, time pressure, urban villager, TCM, and workaholic. Scores on these factors were introduced into the six best models discussed above. The relative contributions of the socio-economic, neighborhood, and attitudinal blocks of variables were assessed. While each block of variables offers some significant explanatory power to the models, the attitudinal variables explained the highest proportion of the variation in the data. The finding that attitudes are more strongly associated with travel than are land use characteristics suggests that land use policies promoting higher densities and mixtures may not alter travel demand materially unless residents' attitudes are also changed.

A Micro-Analysis of Land Use and Travel in Five Neighborhoods in the San Francisco Bay Area

A micro-analysis of land use and travel in five neighborhoods in the San Francisco Bay Area

The purpose of this study is to assess the advantages and limitations of a low-cost, telephone-based traveler information system through the analysis of Fastline, a free, dial-in, traffic information service. Fastline is particularly well suited to this study because, unlike many other Advanced Traveler Information Systems (ATIS), it is already in use in the San Francisco Bay Area. Fastline is easily accessible and requires neither infrastructure development nor technology development; rather, it uses existing infrastructure and technology. This evaluation of the Fastline system is based upon user perceptions of the system's capacity to provide them with the information they need, desire, and will use to help pre-plan trips and encourage changes in trip-making behavior. Changes in trip characteristics, such as route choice, trip start-time, and perhaps, mode choice, may occur based upon the information provided by the system. The key to the study is an assessment of the degree to which users avail themselves of information to consider alternate route and/or mode choice, and to waht degree the alternatives considered effect trip-making behavior. A review of other ATIS projects indicates that there are varying levels of technological complexity and system accuracy leasing to use or non-use of such systems. This research is designed to assess system user's expectations and experiences, as well as the resulting changes, if any, in their trip-making behavior. Thus, the intent of this study is to determine 1) information user's consider important; 2) system use patterns; 3) user's evaluation of the information service attributes such as accuracy, timeliness, and ease of use; and 4) alteration of trip-making behavior due to system information. If a telephone-based forum of Advanced Traveler Information System can produce desired results, it can be implememnted in other urban areas as a low-cost means of helping to reduce traffic congestion, reduce automobile emissions and potentially increase transit use.

An Evaluation Study of a Low-Cost, Telephone-Based Traveler Information System

Author(s): Kitamura, Ryuichi; Laidet, Laura; Mar, Fransisca | Abstract: The purpose of this study is to assess the advantages and limitations of a low-cost, telephone-based traveler information system through the analysis of Fastline, a free, dial-in, traffic information service. Fastline is particularly well suited to this study because, unlike many other Advanced Traveler Information Systems (ATIS), it is already in use in the San Francisco Bay Area. Fastline is easily accessible and requires neither infrastructure development nor technology development; rather, it uses existing infrastructure and technology. This evaluation of the Fastline system is based upon user perceptions of the system's capacity to provide them with the information they need, desire, and will use to help pre-plan trips and encourage changes in trip-making behavior. Changes in trip characteristics, such as route choice, trip start-time, and perhaps, mode choice, may occur based upon the information provided by the system. The key to the study is an assessment of the degree to which users avail themselves of information to consider alternate route and/or mode choice, and to waht degree the alternatives considered effect trip-making behavior. A review of other ATIS projects indicates that there are varying levels of technological complexity and system accuracy leasing to use or non-use of such systems. This research is designed to assess system user's expectations and experiences, as well as the resulting changes, if any, in their trip-making behavior. Thus, the intent of this study is to determine 1) information user's consider important; 2) system use patterns; 3) user's evaluation of the information service attributes such as accuracy, timeliness, and ease of use; and 4) alteration of trip-making behavior due to system information. If a telephone-based forum of Advanced Traveler Information System can produce desired results, it can be implememnted in other urban areas as a low-cost means of helping to reduce traffic congestion, reduce automobile emissions and potentially increase transit use.

/pdf/an-evaluation-study-of-a-low-cost-telephone-based-traveler-1hvbtap8yu.pdf

Laura Laidet

Papers

A Micro-Analysis of Land Use and Travel in Five Neighborhoods in the San Francisco Bay Area

A micro-analysis of land use and travel in five neighborhoods in the San Francisco Bay Area

An Evaluation Study of a Low-Cost, Telephone-Based Traveler Information System

An Evaluation Study of a Low-Cost, Telephone-Based Traveler Information System