Data

Intersection Decision Support Project: Taxonomy of Crossing-Path Crashes at Intersections Using GES 2000 Data

Ragland, David R.
Zabyshny, Aleksandr A.
2003

The Intersection Decision Support (IDS) Project is designed to reduce crossing-path (CP) crashes at intersections by providing crucial information to drivers that would help them avoid such crashes. Over the past decade, researchers have used the General Estimates System (GES, a representative sample of police-reported crashes in the US) and other data sources to develop a taxonomy of CP crashes and pre-crash scenarios as groundwork for crash-prevention efforts. The current study builds on and extends prior work by constructing a taxonomy of CP crashes using data from the 2000 GES and...

Experimental Evaluation of the Continuous Risk Profile (CRP) Approach to the Current Caltrans Methodology for High Collision Concentration Location Identification

Grembek, Offer
Kim, Kwangho
Kwon, Oh Hoon
Lee, Jinwoo
Liu, Haotian
Park, Min Ju
Washington, Simon
Ragland, David
Madanat, Samer M.
2012

This report evaluates the performance of Continuous Risk Profile (CRP) compared with the Sliding Window Method (SWM) and Peak Searching (PS) methods. These three network screening methods all require the same inputs: traffic collision data and Safety Performance Functions (SPFs), however, depending on how these input parameters are analyzed at the network screening level, the result of the analysis can vary significantly. Findings indicated that the CRP method produced far fewer false positives than SWM and PS. The false negative rates for CRP, SWM and PS were comparable. These findings...

Develop a Plan to Collect Pedestrian Infrastructure and Volume Data for Future Incorporation into Caltrans Accident Surveillance and Analysis System Database

Zhang, Yuanyuan
Proulx, Frank R.
Ragland, David R.
Schneider, Robert J.
Grembek, Offer
2014

This project evaluates the feasibility of developing a pedestrian and bicycle infrastructure database and volume database for the California state highway system. While Caltrans currently maintains such data for motor vehicles in the Traffic Accident Surveillance and Analysis System - Transportation System Network (TASAS-TSN) database, the agency does not keep records on pedestrian or bicycle facilities. This information is crucial for improving the safety of these vulnerable road users. This project developed a proposed database structure and corresponding data collection methodology. It...

Guidebook on Pedestrian and Bicycle Volume Data Collection

Ryus, Paul
Ferguson, Erin
Laustsen, Kelly M.
Schneider, Robert J.
Proulx, Frank R.
Hull, Tony
Miranda-Moreno, Luis
2014

NCHRP Report 797: Guidebook on Pedestrian and Bicycle Volume Data Collection is directed to practitioners involved in collecting non-motorized count data. The Guidebook (1) describes methods and technologies for counting pedestrians and bicyclists, (2) offers guidance on developing a non-motorized count program, (3) gives suggestions on selecting appropriate counting methods and technologies, and (4) provides examples of how organizations have used non-motorized count data to better fulfill their missions. The research behind the Guidebook can be found on the TRB website as NCHRP Web-Only...

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...

Understanding Evacuee Behavior: A Case Study of Hurricane Irma

Wong, Stephen
Shaheen, Susan, PhD
Walker, Joan, PhD
2018

In September 2017, Hurricane Irma prompted one of the largest evacuations in U.S. history of over six million people. This mass movement of people, particularly in Florida, required considerable amounts of public resources and infrastructure to ensure the safety of all evacuees in both transportation and sheltering. Given the extent of the disaster and the evacuation, Hurricane Irma is an opportunity to add to the growing knowledge of evacuee behavior and the factors that influence a number of complex choices that individuals make before, during, and after a disaster. At the same time,...

Zero-Emission Bus Implementation Guidebook for California Transit Fleets

Lipman, Timothy, PhD
Rogers, Emily, MS
2023

Transit bus operations in California are experiencing new challenges due to economic conditions and the ongoing global pandemic. A confluence of factors has created a focus on this critical public-needs serving industry, due to state and local efforts to reduce emissions of pollutants and climate-changing gases. Transit bus operations in California provide essential and additional useful services that offer critical mobility to needy populations (elderly and handicapped) as well as many other groups for whom transit buses provide the most economical, convenient, and low-emission options....

AVCEM Documentation Part 3: Review of the Literature on the Private and Social Lifetime Cost of Electric and Alternative-Fuel Vehicle Costs

Shaheen, Susan, PhD
Chan, Nelson
Micheaux, Helen
2021

In order to assess the state of knowledge of the private and social lifetime cost (LC) of conventional and alternative-powertrain vehicles (mainly electric vehicles), we reviewed and evaluated 190 LC studies published between 2000 and 2020. Our main objective was to determine which aspects of the LC of motor vehicles were well researched and well analyzed, and which aspects were less well researched and analyzed and accordingly would benefit most from a focused new research effort; In general, few studies are comprehensive (cover all components of the LC), original (as opposed to reliant...

One-Way Carsharing's Evolution and Operator Perspectives from the Americas

Shaheen, Susan, PhD
Chan, Nelson
Micheaux, Helen
2015

Classic roundtrip carsharing has been documented as a strategy to reduce car ownership and vehicle miles/kilometers traveled in urban areas. The expansion of carsharing and other forms of shared-use mobility have led to a growing interest in understanding the latest models. In recent years, one-way carsharing has gained momentum across the globe with 18 operators providing services in ten countries worldwide. One-way carsharing does not require its users to return the vehicle to the same location from which it was accessed (in contrast to roundtrip carsharing). Users typically pay by the...

Energy and Greenhouse Impacts of Biofuels: A Framework for Analysis

Kammen, Daniel M.
Farrell, Alexander E.
Plevin, Richard J.
Jones, Andrew D.
Nemet, Gregory F.
Delucchi, Mark A.
2008

In this paper, we review some of the basic energy balance and climate change impact issues associated with biofuels. For both the basic energy and greenhouse gas balances of producing and using a range of fuels, and for the increasingly debated and important issues of nongreenhouse gas impacts such as land, fertilizer, and water use, we conclude that an improved framework for the analysis and evaluation of biofuels is needed. These new methodologies and data sets are needed on both physical and socioeconomic aspects of the life-cycle of biofuels. We detail some of components that could be...