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...

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...

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...

Shared Mobility Policy and Modeling Workshop

Shaheen, Susan, PhD
Cohen, Adam
Farrar, Emily
2019

The market for personal mobility is changing rapidly due to shifting social and cultural trends, as well as technological advances, such as smartphones, information processing, widespread data connectivity, sharing, and vehicle automation. Shared, on-demand mobility represents a sustainable vision for future mobility with a reliable network of multimodal options that are available to all travelers. On March 22, 2019, the Local Government Commission (LGC) and the Transportation Sustainability Research Center (TSRC) at the University of California, Berkeley hosted the Caltrans Shared...

Developing Transportation Response Strategies for Wildfire Evacuations via an Empirically Supported Traffic Simulation of Berkeley, California

Zhao, Bingyu
Wong, Steven D.
2021

Government agencies must make rapid and informed decisions in wildfires to safely evacuate people. However, current evacuation simulation tools for resource-strapped agencies largely fail to compare possible transportation responses or incorporate empirical evidence from past wildfires. Consequently, we employ online survey data from evacuees of the 2017 Northern California Wildfires (n=37), the 2017 Southern California Wildfires (n=175), and the 2018 Carr Wildfire (n=254) to inform a policy-oriented traffic evacuation simulation model. We test our simulation for a hypothetical wildfire...

ITS Standards: A System Management Perspective

Intihar, Chris
Hall, Randolf
1997

This working paper is part of a larger project examining how the State of California should respond to the National System Architecture (NSA) for Intelligent Transportation Systems. The specific focus of this paper is on the role of standardization in managing and controlling the transportation system. The paper reviews activities and processes used by standards setting organization in transportation. We conclude that national and international standards will continue to address the needs for defining common interfaces...

Investigation of Vehicles as Probes Using Global Positioning System and Cellular Phone Tracking: Field Operational Test

Yim, Y. B. Youngbin
Cayford, Randall
2001

This paper reports on the first phase of the location technology evaluation for probe vehicles. Two technologies were evaluated, Global Positioning Systems (GPS) and the cellular phone tracking technology developed by US Wireless. Although GPS has shown great potential for vehicle probes, much of the previous research is theoretical in nature. Very little work has been done in the areas of experimental research, implementation or deployment. Most of the field tests were anecdotal; a systematic approach is highly desired to develop a vehicle probe system that is reliable and efficient for...