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

Banerjee, Ipsita
Ragland, David R.

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-cost signs constructed of flexible material. The signs were installed in the medians adjacent to crosswalks at selected non-signalized intersections to instruct drivers to yield the right-of-way to pedestrians. This paper examines the effect on safety characteristics of the intersections of these signs at three stop-sign controlled...

Child Restraint Use: Workbook and Guide for Evaluating Community-based Programs

Ragland, David R.
Geyer, Judy A.
Cooper, Jill F.

The leading cause of injury and death for children in California is motor vehicle crashes. To prevent these needless tragedies, the California Office of Traffic Safety (OTS), through the Business, Transportation and Housing Agency, funds child passenger safety programs throughout the state. This workbook is designed to be used by these local programs to 1) evaluate the impact of their activities on child restraint use, 2) evaluate results to improve or modify the programs as needed, and 3) meet contractual evaluation requirements. Program evaluations can be difficult for local programs due...

Observational Survey of Cell Phone Use and Texting by California Drivers, 2011

Cooper, Jill F.
Ragland, David R.
Ewald, Katrin
Wasserman, Lisa
Murphy, Christopher J.

This methodological report describes survey research and data collection methods employed for the first observational survey of cell phone use and texting by California drivers. This study was conducted by Ewald and Wasserman Research Consultants on behalf of the California Office of Traffic Safety and the Safe Transportation Research and Education Center at the University of California, Berkeley. The goal of the survey was to obtain a statewide, statistically representative observational sample. Vehicle drivers were observed at controlled intersections, such as traffic lights and stop...

Develop Methods to Reduce or Prevent Backing Crashes

Cooper, Douglas L.
Duffy, Sarah
Orrick, Phyllis
Ragland, David R.

Workplace motor vehicle incidents at Caltrans are a significant cause of injuries, employee lost time, and property damage. Because backing crashes are major contributors to motor vehicle incidents, identifying and promoting methods of reducing backing accidents is a top priority. According to internal Caltrans’ data, 92.3% of workplace backing crashes were preventable by the driver. Backing crashes are the single largest category of preventable crashes, representing 30% of preventable crashes in the Caltrans fleet. From 1998 through 2007, preventable backing crashes cost Caltrans at least...

Pedestrian Counting Methods at Intersections: a Comparative Study

Diogenes, Mara Chagas
Greene-Roesel, Ryan
Arnold, Lindsay S.
Ragland, David R.

Resources for implementing countermeasures to reduce pedestrian collisions in urban centers are usually allocated on the basis of need, which is determined by risk studies. They commonly rely on pedestrian volumes at intersections. The methods used to estimate pedestrian volumes include direct counts and surveys, but few studies have addressed the accuracy of these methods. This paper investigates the accuracy of three common counting methods: manual counts using sheets, manual counts using clickers, and manual counts using video cameras. The counts took place in San Francisco. For the...

Pedestrian and Bicycle Safety Evaluation in a SMART Corridor

Ragland, David R.
O’Connor, Terri

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

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.

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....

Pedestrian Safety Improvement Program

Grembek, Offer
Bosman, Craig
Bigham, John M.
Fine, Sara
Griswold, Julia B.
Medury, Aditya
Sanders, Rebecca L.
Schneider, Robert J.
Yavari, Afsaneh
Zhang, Yuanyuan
Ragland, David R.

The Pedestrian Safety Improvement Program is an effort of the California Department of Transportation (Caltrans) to identify and address systemic problems with regard to pedestrian safety in California, with the long-term goal of substantially reducing pedestrian fatalities and injuries in California. The efforts and findings presented in this report reflect the work of a team of experts in transportation engineering, transportation planning, public health, geographic information systems, and urban design from the UC Berkeley Safe Transportation Research & Education Center.

Ten Years Later: Examining the Long-Term Impact of the California Safe Routes to School Program

Ragland, David R.
Pande, Swati
Bigham, John M.
Cooper, Jill F.

California was the first state to legislate a Safe Routes to School (SR2S) program under Assembly Bill AB 1475 (1999). SR2S funds construction projects that make it safer for children to walk/ bicycle to school and encourage a greater number of children to choose these modes of travel for the school commute. The main goal of this project was to assess the long-term impact of program-funded engineering modifications on walking/bicycling levels and on safety. Evaluation of improvements was determined using a targeted method of determining the countermeasures to result in safety and mode...