Data

Pedestrian-involved crashes that occurred in the city of San Francisco over a six-year period, 2002–2007, were analyzed to examine various influential factors on the injury severity of pedestrian crashes. The crash data extracted from the Statewide Integrated Traffic Records System (SWITRS) include five categorical levels of injury severity in traffic crashes also in addition to detailed information about the features of each crash. This study applied an ordered probit model for injury severity analysis to specify the ordinal nature of injury categories. To draw unbiased implications from...

Bicycle volume data are useful to practitioners and researchers to understand safety, travel behavior, and development impacts. This paper describes the methodology used to develop several simple models of bicycle intersection volumes in Alameda County, California. The models are based on two-hour bicycle counts performed at a sample of 81 intersections in the Spring of 2008 and 2009. Study sites represented areas with a wide range of population density, employment density, proximity to commercial property, neighborhood income, and street network characteristics. The explanatory variables...

In this talk, an overview of the recently completed National Cooperative Highways Research Program project 07-19 will be presented. In NCHRP 07-19, research was conducted on a variety of methods and technologies for collecting bicyclist and pedestrian volume data. Research included a practitioner's survey, in-depth interviews with count program managers, and field testing and accuracy evaluation of six counting technologies. Counters were installed at roughly 15 different sites and evaluated for precision and reliability. The main product of this project is a guidebook on conducting counts...

Freeway collisions are thought to be affected by traffic states. To reduce the number of collisions, the study to reveal how the traffic states influence collisions are required. Therefore, the purpose of the paper is to suggest a method to relate traffic states to collision frequency in freeway. We first defined section- based traffic phases showing traffic state of a section using upstream and downstream traffic states: free flow (FF), back of queue (BQ), bottleneck front (BN) and congestion (CT). Secondly, by integrating freeway collision data and traffic data from the California PeMS...