Data collection

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

Ragland, David R.
Geyer, Judy A.
Cooper, Jill F.
2003

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...

Attribution of functional limitation to cancer decreases in the year following breast cancer diagnosis in older patients

Sehl, Mary E.
Satariano, William A.
Ragland, David R.
Reuben, David B.
Naeim, Arash
2008

Objectives: To examine the prevalence of self-reported functional limitations in a breast cancer population, identify whether these reported limitations are attributed to breast cancer versus other coexisting illnesses, and examine how this attribution changes over time from early in treatment to 9 months later.

Design: Longitudinal, observational study.

Setting: Community dwelling adults in Detroit metropolitan area. Participants: 2033 participants (1011 breast cancer patients, 1022 controls) aged 40–84 years.

Measurements: Participants were asked about each of 23...

California Traffic Safety Survey 2022

Ewald, Katrin
Wasserman, Lisa
2022

Ewald & Wasserman Research (E&W) conducted the 2022 California Traffic Safety Public Opinion Study on behalf of the California Office of Traffic Safety (OTS) and the Safe Transportation Research and Education Center of UC Berkeley (SafeTREC). Similar to previous years and since 2020, the data collection transitioned from an intercept survey to an online panel with survey panelists provided by Marketing Services Group, a commercial sample and panel vendor.

Panelists consisted of California drivers who were forwarded to an online survey portal programmed and managed by E&W...

Using Variable Speed Limits To Reduce Rear-End Collision Risks Near Recurrent Bottlenecks

Li, Zhibin
Liu, Pan
Bigham, John M.
Ragland, David R.
2013

Rear-end collisions would occur if vehicle speeds decrease abruptly when encountering kinematic waves (KWs) emanating from active bottlenecks. This study aims to develop a control strategy in variable speed limits (VSL) to reduce rear-end collision risks near recurrent bottlenecks. Using the crash prediction model developed for rear-end collisions related to risky KWs, the effectiveness of VSL control strategies were evaluated in the cell transmission model (CTM). Several strategies were tested in sequence to determine the best case for risk reduction. Results of this study show that the...

Developing Safety Management Tools for State Departments of Transportation

Chung, Koohong
Grembek, Offer
Lee, Jinwoo
Choi, Keechoo
2013

Two safety management tools have recently been developed for the California Department of Transportation (Caltrans). One is the continuous risk profile (CRP) approach, which is a network screening procedure, and the other is the California Safety Analyst (CASA), a web-based application designed to assist state safety engineers in conducting safety investigations and in documenting their findings. This paper provides a qualitative description of the two tools and summarizes feedback from more than 100 Caltrans safety engineers who attended demonstrations of the web-based application....

A Multidimensional Clustering Algorithm for Studying Fatal Road Crashes

Fishbain, Barak
Grembek, Offer
2014

Road fatalities are rare outcomes of events that occur in a small time-space region. Although the exact chain of events for each fatality is unique, there are inherent similarities between road fatalities. The science of road safety is dedicated to identifying such similarities, mainly using statistical analysis tools. Researchers typically analyze patterns that emerge over space, such as hot-spot studies, or patterns that emerge over time, such as before-after studies. Traffic research enumerates 84 parameters that characterize a road fatality. A vast number of papers have tried to...

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....

The Impact of Health Problems on Driving Status Among Older Adults

MacLeod, Kara E.
Satariano, William A.
Ragland, David R.
2014

Objective: This study assessed the impact of health problems on driving status (current driver vs. ex-driver) among older adults to identify which of those health problems have the greatest individual and population impact on driving cessation.

Methods: Data were from baseline and a 5 year follow-up wave of a longitudinal survey of adults aged 55 years and older (N¼1279). The impact of several health problems on driving status was assessed using a relative risk ratio and a population attributable risk percent. Analyses controlled for age, gender, and the presence of additional...

Crashes on and Near College Campuses: A Comparative Analysis of Pedestrian and Bicyclist Safety

Loukaitou-Sideris, Anastasia
Medury, Aditya
Fink, Camille
Grembek, Offer
Shafizadeh, Kevan
Wong, Norman
Orrick, Phyllis
2014

Problem, research strategy, and findings: College campuses are multimodal settings with very high levels of walking and biking in conjunction with high levels of vehicular traffic, which increases risks for bicyclists and pedestrians. In this study, we examine crash data (both police reported and self-reported) and urban form data from three U.S. campuses to understand the spatial and temporal distribution of crashes on the campuses and their immediate periphery. To account for underreporting of pedestrian and bicycle crashes, we developed and circulated an online survey, which helped...

Relative Vulnerability Matrix for Evaluating Multimodal Traffic Safety

Grembek, Offer
2015

The multimodal transportation network includes a mix of inherently different modes. In addition to differences in price, range, and comfort of travel, these modes differ in mass and velocity, which correspond to different orders of magnitude in the kinetic energy carried. This discrepancy in kinetic energy affects both the level of protection of each mode, and the level of damage it can inflict on users of other modes. Unfortunately, accounting for both sides of a crash is often overlooked. While the quantities and variables of collected data continue to increase, the analyses conducted...