Environment

Evaluation of the Safe Routes to Transit Program in California

Weinzimmer, David
Sanders, Rebecca L.
Dittrich, Heidi
Cooper, Jill F.
2014

This paper elaborates on findings from an evaluation of the San Francisco Bay Area’s Safe Routes to Transit (SR2T) program, which funded enhancements to increase walking and cycling to regional transit stations. To understand how the program influenced travel choices, behavior, and perceptions of safety and local air quality, researchers surveyed transit users and observed driver, pedestrian, and bicyclist behavior in the periods before and after the enhancements were made at multiple transit stations. Data from the treatment and control stations suggest that the streetscape and roadway...

A Methodology of Quantifying Precipitation Exposure for Wet-Weather Collisions and Evaluating Effectiveness of Open-Grade Asphalt Concrete as a Countermeasure

Chan, Ching-Yao
Jin, Eui-Jae
Oh, Soon Mi
Ragland, David R
2010

Weather-related crashes represent a significant concern in roadway safety. Wet collisions often resulted in injuries or fatalities, at a ratio higher than collisions that occur in dry roadway conditions. Therefore, it is of strong interest to identify and manage the locations where collisions are prone to happen under wet pavement surface or adverse weather conditions. This paper introduces a method to estimate precipitation exposure of roadway segments by linking weather station data to collision database. Subsequently, the corresponding crash rate for a subject location is calculated...

Roadway and Infrastructure Design and Its Relation to Pedestrian and Bicycle Safety: Basic Principles, Applications, and Benefits

Ragland, David R
Grembek, Offer
Orrick, Phyllis
Felschundneff, Grace
2013

Road deaths are forecast to double by 2020, with the burden falling most heavily on low- and middle-income countries and, within those countries, on the most vulnerable and poorest road users. Half of the 1.2 million people killed and 50 million injured in road crashes each year are pedestrians, motorcyclists, bicyclists, and users of unsafe public transport; and more than 90 percent are from low- and middle-income countries. Because these are the areas where rapid motorization is taking place, the issue of safety in increasingly multi-modal environments is now of critical importance,...

Documenting Targeted Behaviors Associated with Pedestrian Safety

Cooper, Jill F.
Schneider, Robert J.
Ryan, Sherry
Co, Sean
2013

The purpose of this study is to provide an exploratory analysis of the proportion of pedestrians, bicyclists, and drivers exhibiting four specific behaviors at 12 intersections near transit stations in 4 the San Francisco Bay Area. The target behaviors include: 1) pedestrians crossing the roadway while using a mobile device, such as a cell phone, 2) pedestrians crossing a signalized intersection against a red light, 3) bicyclists running a red light at a signalized intersection, and 4) automobiles turning right on red without stopping. These four behaviors are important because they may...

Estimating Pedestrian Accident Exposure: Protocol Report

Greene-Roesel, Ryan
Diogenes, Mara Chagas
Ragland, David R
2007

Walking is a healthful, environmentally benign form of travel, and is the most basic form of human mobility. Walking trips account for more than 8 percent of all trips taken in California, making walking the second most commonly used mode of travel after the personal automobile (Caltrans, 2002). In addition, many trips made by vehicle or public transit begin and end with walking. In spite of the importance and benefits of walking, pedestrians suffer a disproportionate share of the harm of traffic incidents in California. As noted above, walking trips make up just 8 percent of all trips in...

Evaluating the Public Perception of a Feebate Policy in California through the Estimation and Cross-Validation of an Ordinal Regression Model

Martin, Elliot, PhD
Shaheen, Susan, PhD
Lipman, Timothy
Camel, Madonna
2014

Understanding the roots of policy perception can be critical for informing the design and implementation of innovative public policies; Feebates is one such innovative policy and in the context of new vehicles can be designed to offer buyers a rebate for the purchase of low-emission vehicles and a fee for the purchase of high-emission vehicles; Because feebates is a policy that directly impacts the consumer, understanding the dynamics of public perception, support, and opposition is important; This study explores the public perception of a feebate policy within California and evaluates the...

Biofuel Boundaries: Estimating the Medium-Term Supply Potential of Domestic Biofuels

Jones, Andrew
O'Hare, Michael
Farrell, Alexander
2007

We estimate the physical supply potential of biofuels from domestic municipal solid waste, forestry residues, crops residues and energy crops grown on existing cropland using optimistic assumptions about near-term conversion technologies. It is technically feasible to produce a significant amount of liquid biofuel (equivalent to 30-100% of 2003 gasoline demand) without reducing domestically produced food and fiber crops or reducing the total calories available as domestic animal feed. Most of this supply can be attributed to the potential of energy crops, with the combination of municipal...

Impacts of Transportation Network Companies on Vehicle Miles Traveled, Greenhouse Gas Emissions, and Travel Behavior Analysis from the Washington D.C., Los Angeles, and San Francisco Markets

Martin, Elliot, PhD
Shaheen, Susan, PhD
Stocker, Adam
2021

Transportation Network Companies (TNCs) like Lyft, Uber, and their global counterparts have expanded around the world over the past decade and have changed the way that people travel around cities and regions. The individual mobility benefits provided by TNCs have been clear. Passengers can summon a vehicle quickly via smartphone from almost anywhere to take them almost anywhere, with advance communication on estimated wait time, travel time, and cost. TNCs may also provide users with added mobility benefits, especially for those living in areas where public transit service is infrequent...

A Low-Carbon Fuel Standard for California Part 1: Technical Analysis

Farrell, Alexander E.
Sperling, Daniel
Arons, S.M.
Brandt, A.R.
Delucchi, M.A.
Eggert, A.
Farrell, A.E.
Haya, B.K.
Hughes, J.
Jenkins, B.M.
Jones, A.D.
Kammen, D.M.
Kaffka, S.R.
Knittel, C.R.
Lemoine, D.M.
Martin, E.W.
Melaina, M.W.
Ogden, J.M.
Plevin, R.J.
Sperling, D.
Turner, B.T.
Williams, R.B.
Yang, C.
2007

Executive Order S-1-07, the Low Carbon Fuel Standard (LCFS) (January 18, 2007), calls for a reduction of at least 10 percent in the carbon intensity of California’s transportation fuels by 2020. It instructed the Secretary of the California Environmental Protection Agency to coordinate activities between the University of California, the California Energy Commission (CEC) and other state agencies to develop and propose a draft compliance schedule to meet the 2020 Target. This report is the first of two by the University of California in response. This first study assesses the low-carbon...

Exploring the Future of Integrated Transportation Systems in the United States from 2030 to 2050: Application of a Scenario Planning Tool

Shaheen, Susan, PhD
Camel, Madonna
Lee, Kunik
2013

Intelligent transportation systems (ITS) have primarily focused on systems management. To further improve connectivity and safety in the future, ITS might embrace a more holistic planning approach. While the future of ITS remains an open question, its evolution is closely linked to how the world evolves on many dimensions, social, political, economic, legal, and environmental. In this paper, the authors present results from four expert workshops. These consisted of an initial steering committee workshop (February 2011), two expert scenario-planning workshops (June 2011), and a final...