Transportation

 

 

 Valuing Rail Transit: Comparing Capital and Operating Costs to consumer Benefits

A certain acrimony pervades the longstanding debate over the costs and benefits of public rail transportation in the United States. Some seem opposed to all rail transit all the time, while others support any and every rail project, despite sometimes high costs and low ridership. With much of the debate focused on pricing automobile externalities, transportation choice, and the rail’s external benefits, surprisingly few studies assess which rail transit systems create net positive social welfare. If consumer benefits alone do not justify the high cost of a transit investment, what would the external value of a passenger trip have to be to do so?

Combining fare, ridership, operating, and capital cost data for 24 transit agencies' heavy and/or light rail systems, this paper makes back-of-the-envelope estimates of how transit systems' rider benefits compare to operating deficits. Urban rail systems may not be optimal from a transportation systems or economic cost-benefit perspective, but they clearly create value for consumers and society. Given a low, but commonly applied, elasticity of -0.3 and a linear demand curve, two transit systems create net social welfare gains based solely on consumer surplus. At least ten others likely provide net benefits when accounting for economic externalities. At an elasticity of -0.6, no system provides net social welfare gains without accounting for externalities. At least five systems are unlikely to provide net economic benefits, even given generous assumptions about external and rider benefits.


 

Suburban Transformations: From Employment Centers to Mixed-Use Activity Centers

Some U.S. edge cities are experiencing a second generation of development – a makeover of strategic infill, land-use diversification and often transit-orientation and pedestrian-friendly streetscape design. This research will use 1990 and 2000 census data to create a typology of Employment Centers (ECs) in the San Francisco Bay Area, focusing on changes in development scale, densities, land-use mixes, employment compositions, and site-design elements during the 1990s. EC prototypes, such as “second-generation mixed-use edge cities” and “single-use office parks”, will be identified using cluster analysis techniques. Changes in commuting choice and behavior during the 1990s will be measured for each EC prototype, using metrics related to modal splits, commute distances and durations, and VMT/employees as well as estimated fuel consumption, mobile-source emissions, and greenhouse gas emissions. Case-study work will probe the influences of market forces (e.g., housing targeted at professional workers) and planning interventions (e.g., rezoning, infrastructure provisions) in explaining why and how different ECs underwent different land-use and employment transformations during the 1990s. The research will shed important light on the broader transportation and environmental policy implications of land-use transformations among traditional employment centers in U.S. metropolitan areas.


 

 Histories of Transit-Oriented Development: Perspectives on the Development of the TOD Concept


 

 The Effects of Transportation Corridors' Roadside Design Features on User Behavior and Safety, and Their Contributions to Health, Environmental Quality, and Community Economic Vitality: a Literature Review 

The purpose of this study is to identify quantifiable performance measures for transportation corridor design features related to safety, economic vitality and community quality of life. The results of this study will support Caltrans planning, design, and implementation of transportation corridors responsive to the contextual environments of Caltrans partner communities and will provide a model for transportation and urban planners and designers.

A key aspect of the study will be to identify a corridor on which we will conduct research that collects data on performance measures identified in previous research. Initial roadway types for study are arterials and "main street" highways, with a focus on roadways that are within Caltrans' jurisdiction. The study will investigate how individual design features and the shaping of whole environments can influence and result in specific behaviors and benefits.


 

 Are TODs Over-Parked?

Recent studies on car ownership levels and vehicle trip generation rates suggest that many large-scale housing projects near urban rail stations are “over-parked” – more parking is provided than is needed. This can drive up the cost of housing, consume valuable land near transit stops, and impose such environmental costs as increased impervious surface area. Part of the blame for the over-supply of parking in transit-oriented developments (TODs) could be the reliance on ITE parking generation figures. This research compares actual parking demand with parking supplies and ITE rates for 20 large-scale multi-family housing projects in four rail-served metropolitan areas: Portland, San Diego, San Francisco, and Washington, D.C. The impacts of over-supplying parking on housing affordability, project profitability, land consumption, environmental pollution, travel demand, and other areas will be explored. This will be supplemented by case studies on the evolution of zoning and building codes in TODs, including their rationales, institutional and political contexts, influences on TOD planning and designs, and views of local residents. Based on both quantities and qualitative results, possibilities for various reforms – such as transit eco-pass substitutions, unbundling parking and housing provisions/costing, flexible parking codes, and near-site carsharing – will be examined.