Safety

Low Income Childhood Pedestrian Injury: Understanding the Disparate Risk

Johnson, Emily
Geyer, Judy A
Rai, Nirmeet
Ragland, David R
2004

A leading cause of death and injury to children is being struck by a motor vehicle. A disproportionate number of injured child pedestrians are of low socioeconomic status. The relationship between socioeconomic status and pedestrian injury is poorly understood. The existing literature is limited by the lack of pedestrian exposure data, a common measure of risk, and a clear conceptual framework for the interaction between socioeconomic status and pedestrian injury. Another issue is the limited availability of injury data. This paper proposes a model for understanding child pedestrian...

What They Don’t Know Can Kill Them

Mitman, Meghan Fehlig
Ragland, David R.
2007

Traffic safety researchers have long argued that driver behavior outweighs physical elements (such as road design) as a causal factor in motor vehicle collisions. A fundamental causal component of pedestrian-vehicle collisions is also behavior—that of the driver and that of the pedestrian. One determinant of this behavior may be whether the driver, the pedestrian, or both understand the motor vehicle code, which demarcates right-of-way in pedestrian-vehicle interactions. That is, inappropriate or unlawful behavior may occur because the law is not understood or is misunderstood. Previous...

The Analysis of Right-of-way for different road users in China: Passing-Passenger-Unit Versus Passenger-Car-Unit

Xiong, Wen, Professor
Zhang, Yuanyuan, PhD
Chen, Xiaohong, Professor
Jiang, Chao
2014

Being a public resource, the roadway space was distributed between different road users based on the Passenger-Car-Unit (PCU) concept. However, this concept tends to under estimate the capacity of public transportation and non-motorized travel. To improve the traditional car-oriented design to become more human-oriented, this study proposed a Passing-passenger-unit (PPU) and the method to observe the PPU in roadway level and area level. The PPU data were collected for urban arterials and residential areas in China to test the method and to compare the right-of-way distribution at different...

Evaluation of Countermeasures: A Study on the Effect of Impactable Yield Signs Installed at Intersections in San Francisco

Banerjee, Ipsita
Ragland, David R.
2007

The present study evaluated the effect of impactable signs that used the yield-symbol as approved by the National Committee on Uniform Traffic Control Devices (NCUTCD) in the 2003 Manual of Uniform Traffic Control Devices (MUTCD). Impactable yield signs are low- costsignsconstructed of flexible material. The signs wereinstalled in the medians adjacent to crosswalks at selected non-signalized intersections to instruct drivers to yield the right-of-way to pedestrians. This paperexamines the effect on safety characteristics of the intersections of these signs at three stop-sign controlled...

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...

Safe Routes to Transit Program Evaluation Final Report

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

Safe Routes to Transit (SR2T) was initiated in 2004 with the adoption of the San Francisco Bay Area’s Regional Measure 2 which established a $1 increase in Bay Area bridge tolls. The intended purpose of this funding was to support various transportation projects within the region in order to reduce congestion along the seven state-owned toll bridge corridors. Consistent with this purpose, the SR2T Program was awarded $20 million to fund enhancements to increase walking and cycling to regional transit stations.SR2T funds were used for the following improvements, among others: ssecure...

Identifying Factors that Determine Bicyclist and Pedestrian-Involved Collision Rates and Bicyclist and Pedestrian Demand at Multi-Lane Roundabouts

Arnold, Lindsay S.
Flannery, Aimee
Ledbetter, Lauren
Bills, Tierra
Jones, Michael G.
Ragland, David R.
Spautz, Laura
2013

This project examined the safety and demand issues for pedestrians and bicyclists at multi-lane roundabouts through a literature review, case studies, in-field counts and surveys, focus groups, and video analysis. This document presents research findings, synthesizes current information on best practices, and makes recommendations to assist local agencies planning and designing safer multi-lane roundabouts. These findings should help local agencies and Caltrans create roundabouts that better and more safely address the needs of bicyclists and pedestrians. The current literature is referred...

HOV Lane Configurations and Safety Performance of California Freeways – An Investigation of Differential Distributions and Statistical Analysis

Jang, Kitae
Chan, Ching-Yao
2009

From a recent study of safety evaluation of HOV-equipped freeways, it was found that limited-access HOV lanes appear to have a safety performance disadvantage when measured by collision distribution or collision rates for the HOV lane alone and for the HOV and left lanes combined. This paper describes the work performed to verify the statistical significance of related findings. Several statistical tests were used: empirical cumulative density function (CDF), Kolmogorov-Smirnov Tests, and comparison of means based on Poisson Distributed Samples. The conclusion that continuous-access HOV...

Impact of Pedestrian Presence on Movement of Left-Turning Vehicles: Method, Preliminary Results & Possible Use in Intersection Decision Support

Banerjee, Ipsita
Shladover, Steven E
Misener, James A
Chan, Ching-Yao
Ragland, David R
2004

Warning systems are being developed for left-turning vehicles at intersections where protected left-turns are not warranted or cannot be provided, based on limitations of right of way or intersection capacity. These are meant to provide warnings to left-turning vehicles of vehicles approaching from the opposite direction, when the time to turn may be deemed unsafe. To implement these warning systems, it is necessary to estimate in near real time, the probability of conflict between the two approaching vehicles. A study is being conducted with the help of video and radar at various...

Community Pedestrian Safety Engagement Workshops in California

Babka, Rhianna JoIris
Cooper, Jill F
Alfsen, Wendy
Sabin, Marilyn
2011

The Community Pedestrian Safety Engagement Workshops are a community capacity building program to involve local residents in community pedestrian safety. The focus of these workshops is to engage, educate and empower residents to ensure they have the skills, knowledge and resources they need to become active in improving pedestrian safety in their neighborhood, district, city or county. This program uses pedestrian planning and community engagement curriculums as a framework for the content, and goes beyond this to tailor each workshop to the individual community needs, ensuring genuine...