Safety

Driver and Pedestrian Behavior at Uncontrolled Crosswalks in the Tahoe Basin Recreation Area

Mitman, Meghan Fehlig
Cooper, Douglas
DuBose, Brooke
2010

For more than thirty years, pedestrian safety studies have considered pedestrian-vehicle collision patterns and pedestrian and driver behavior at marked and unmarked crosswalks at uncontrolled crossings. Recent research in this area conducted by the UC Berkeley Traffic Safety Center [aka SafeTREC] on behalf of Caltrans, and summarized in a 2008 Transportation Research Record paper by Mitman et al., “The Marked Crosswalk Dilemma: Uncovering Some Missing Links in a 35-Year Debate,” was designed to fill key gaps in the literature by analyzing driver/pedestrian behavior and knowledge of right-...

Providing Intersection Decision Support under Challenging Conditions

Shladover, Steven E.
VanderWerf, Joel
Ragland, David R.
2005

This paper describes the results of simulation studies to determine how effectively left-turning drivers can be alerted to imminent conflicts with opposing traffic under difficult operating conditions and with limited detector capabilities. These conditions include approaching vehicles changing speed in locations that are not covered by detectors and detectors that may only be able to detect vehicle presence, but not speed. In cases without direct speed detection, one may try to rely on historical speed statistics to estimate the speed of approaching traffic, but unless the approach speeds...

Complete Streets: From Policy to Practice in the San Francisco Bay Area

Pande, Swati, M.S.,MPP
Martinez, Martin MPP
2014

This paper describes how regional funding guidelines can affect local adoption of Complete Streets projects. The Metropolitan Transportation Commission (MTC), the regional Metropolitan Planning Organization for the nine-county Bay Area region in California, has developed a funding approach called the One Bay Area Grant (OBAG) for the allocation of funds for the 2012-2016 Congestion Mitigation and Air Quality (CMAQ) and Surface Transportation Program (STP) across the Bay Area. Each jurisdiction receiving funding through OBAG was required to demonstrate compliance with Complete Streets (CS)...

Gap acceptance for vehicles turning left across on-coming traffic: Implications for Intersection Decision Support design

Ragland, David R.
Arroyo, Sofia
Shladover, Steven E.
Misener, James A.
Chan, Ching-Yao
2005

A left-turning vehicle (Subject Vehicle, SV) attempting to cross the path of an oncoming vehicle (Principal Other Vehicle, POV) at an intersection typically does not have the right of way. The main task of the SV driver is to find an adequate opportunity in opposing traffic to initiate the left-turn maneuver. To reduce the probability of a conflict, warning systems, such as Intersection Decision Support (IDS) systems, are being developed. These systems alert drivers of SV vehicles attempting to negotiate a left turnabout traffic approaching from the opposite direction. The current paper (i...

Rural Road Links: A Review on Current Research Projects & Initiatives Aimed at Reducing Vehicle Crash Fatalities on Rural Roads

Quiros, Lesliam
Shaver, Barrett
2003

Rural America accounts for a smaller and more dispersed portion of the nation’s population, yet it comprises a considerable portion of the transportation system. Rural areas account for approximately 83 percent of the land in the U.S and their roads account for 80 percent of the total U.S. road mileage and 40 percent of the vehicle miles traveled. Fatalities on rural roads surpass those in urban areas, even though urban areas are more densely populated and consequently, have a higher traffic flow. In 2001 alone, fatal crashes on rural areas accounted for 61 percent of all traffic...

Estimating Bicycle and Pedestrian Demand in San Diego

Jones, Michael
Buckland, Lauren
2008

This paper introduces the concepts behind estimating bicycle and pedestrian demand and provides an example of the development of a sketch-plan method for estimating bicycle and pedestrian demand from land use in San Diego County. The paper describes the methodology involved in collecting counts for the currently ongoing Seamless Travel project. The Seamless Travel project intends to develop a model for estimating bicycle and pedestrian demand within San Diego County. The project methodology includes conducting bicycle and pedestrian counts and intercept surveys over a two-year period...

Assessing the Variation of Curbside Safety at the City Block Level

Medury, Aditya PhD
Vlachogiannis, Dimitris
Grembek, Offer, PhD
2020

Investigating the dynamics behind the likelihood of vehicle crashes has been a focal research point in the transportationsafety field for many years. However, the abundance of data in today's world generates opportunities for deepercomprehension of the various parameters affecting crash frequency. This study incorporates data from many differentsources including geocoded police-reported crash data, curbside infrastructure data and socio-demographic data for thecity of San Francisco, CA. Findings revealed that the GFMNB model provides a better statistical fit than the FMNB andNB model in...

Traffic Injury on Tribal Lands in California

Ragland, David, PhD, MPH
Bigham, John
Oum, Sang Hyouk
Chen, Katherine
Felschundneff, Grace
2014

There is a disproportional risk of motor vehicle death and injury among American Indian/Alaska Native (AI/AN) populations in the United States. As home to the nation’s largest population of AI individuals, it is vital that California develop a better understanding of the factors contributing to this risk to guide the development and implementation of interventions to improve traffic safety for this population on the nearly 100 Rancherias and reservations in the state. However, there is very little data about the numbers and types of collisions, and driver and environmental factors...

Evaluation of Injury Severity Updates in California Collision Data

Bigham, John
Oum, Sang Hyouk
2018

Fatal or injury collisions in California must be reported to the California Highway Patrol (CHP) for inclusion in the Statewide Integrated Traffic Records System (SWITRS). After records have been entered into SWITRS they are made publicly available and are accessible through the CHP’s report and data retrieval site called I-SWITRS. However, records accessed in SWITRS are considered provisional and can be updated several years after initial entry. This includes the injury severity level of collisions. If the collision data was accessed prior to an injury severity update, the agency...

Effects of Weather Variables on Pedestrian Volumes in Alameda County, California

Attaset, Vanvisa
Schneider, Robert J.
Arnold, Lindsay S.
Ragland, David R.
2010

Accurate estimates of pedestrian volume are important for analyzing pedestrian movement and safety; methods to estimate these volumes are continuously evolving and being improved. However, relatively little is known about the impact of weather conditions on pedestrian activity. This paper evaluates the effect of weather by including temperature, cloud cover, wind, and precipitation variables in a linear regression model of pedestrian volumes. Pedestrian volumes were collected over approximately one year using automated counters at 13 different locations in Alameda County, California. These...