Road User Behavior

On The Legal Deterrence Of Pedestrian Hit-and-Run Collisions

Grembek, Offer
Griswold, Julia B.
2012

Hit-and-run collisions—those in which a driver involved in the collision leaves the scene before the arrival of law enforcement officials—are a unique type of traffic violation because the driver's decision is a question of damage control rather than damage prevention. To reduce hitand-run violations, individual state laws impose legal sanctions to deter drivers from leaving the collision scene prematurely. Deterrence Theory dictates that compliance with laws is associated with the certainty, severity, and swiftness of punishment. The purpose of this study is to explore the deterrent...

Pedestrian and Bicycle Safety Evaluation in a SMART Corridor

Ragland, David R.
O’Connor, Terri
2007

The San Pablo/I-80 corridor is a “SMART” transportation corridor that extends about 20 miles along the eastern shore of the San Francisco Bay. The corridor uses Intelligent Transportation System (ITS) technologies to increase and enhance transportation mobility.

The goal of the SMART Corridor Plan was to improve vehicle mobility throughout the corridor. Since the plan focused almost exclusively on vehicular traffic, achieving these goals has the potential to raise the risk of injury to pedestrians and bicyclists without thorough analysis of the overall effects of the SMART corridor...

Evaluation of Wet Weather Accident Causation Criteria

Oh, Soonmi
Ragland, David R.
Chan, Ching-Yao
2008

This report documents findings from analysis of traffic collision data from sites that display high collision rates only under wet pavement conditions. These sites were selected using Caltrans safety engineers’ field reports, Wet Table C “investigation required” locations, and a new approach called Continuous Risk Profile (CRP). The geometric features at the sites were studied via field visits and review of as-built plans. Rapid spatial changes (i.e., vertical and horizontal curve in short distance), narrower lane width, lack of median, and wider total freeway width were some of the...

Safety Evaluation of High-Occupancy Vehicle (HOV) Facilities in California

Ragland, David R.
Oh, Soonmi
Chan, Ching-Yao
2008

This report documents findings from analysis of traffic collision data from sites that display high collision rates only under wet pavement conditions. These sites were selected using Caltrans safety engineers’ field reports, Wet Table C “investigation required” locations, and a new approach called Continuous Risk Profile (CRP). The geometric features at the sites were studied via field visits and review of as-built plans. Rapid spatial changes (i.e., vertical and horizontal curve in short distance), narrower lane width, lack of median, and wider total freeway width were some of the...

Crosswalk Confusion: More Evidence Why Pedestrian and Driver Knowledge of the Vehicle Code Should Not Be Assumed

Mitman, Meghan F.
Ragland, David R.
2014

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 the right-of-way in pedestrian-vehicle interactions. That is, inappropriate or unlawful behavior may occur because the law is not understood or is misunderstood....

Transportation and Health: Policy Interventions for Safer, Healthier People and Communities

Ragland, David R.
Orrick, Phyllis
2011

The public road system in the U.S. is the world’s busiest, sustaining more than 3 trillion vehiclemiles of travel each year on a network of more than 4 million miles of roads and highways. It has had enormous positive impacts on U.S. society, driving economic growth and innovation, providing mobility and opportunity to its users, and helping the U.S. maintain its global economic competitiveness. This system was built with a focus on motor vehicles; only recently has substantial funding and attention been given to transit, walking, and bicycling. There is still a huge disparity in how we...

The Marked Crosswalk Dilemma: Uncovering Some Missing Links in a 35-Year Debate

Mitman, Meghan F.
Ragland, David R.
Zegeer, Charles V.
2008

Largely in response to several landmark safety studies, as an official or unofficial policy, many agencies across the U.S. have elected to remove marked crosswalks at uncontrolled intersections, or have shown resistance to installing them in the first place. This approach results in unacceptable pedestrian mobility restrictions, yet such restrictions are often not considered in policy-making. As such, there is a need for roadway system owners to develop strategic safety guidelines to address the marked crosswalk dilemma.

Since 2005, the UC Berkeley Traffic Safety...

Driving Cessation and Increased Depressive Symptoms

Ragland, David R.
Satariano, William A.
MacLeod, Kara E.
2003

Background. To understand the consequences of driving cessation in older adults, the authors evaluated depression in former drivers compared with active drivers.

Methods. Depression (as assessed using the Center for Epidemiological Studies Depression Scale), driving status, sociodemographic factors, health status, and cognitive function were evaluated for a cohort of 1953 residents of Sonoma County, California, aged 55 years and older, as part of a community-based study of aging and physical performance. The authors reinterviewed 1772...

Problems With Vision Associated With Limitations or Avoidance of Driving in Older Populations

Satariano, William A.
MacLeod, Kara E.
Kohn, Theodore E.
Ragland, David R.
2004

Objectives. This report examines the role of (a) disease processes affecting vision, (b) reported troubles with vision, (c) physical symptoms affecting the eyes, and (d) objective measures in reported driving limitation due to problems with eyesight among older drivers.

Methods. Data for this study (N 1⁄4 1,840) were obtained from participants in a community-based study of aging and physical performance in people age 55 or older in the city of Sonoma, California. Each of 16 visual conditions was...

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...