Training and education

Keeping Children Safe in Cars

Cooper, Jill F.
2004

Low-income children face twice the risk of dying from crash-related injuries compared to children from higher income families. To increase safety for these children, the California Health Care Safety Net Institute and the UC Davis Medical Center launched the Child Passenger Safety (CPS) Initiative with funding from the California Office of Traffic Safety. The initiative ran from April, 2001, through September, 2003, and had these goals: to increase safety seat use among families using public health care services; to decrease the rate of safety seat misuse among these families; and to...

Exploring Factors Influencing Bicyclists’ Perception of Comfort on Bicycle Facilities

Li, Zhibin
Wang, Wei
Zhang, Yuanyuan
Lu, Jie
Ragland, David R.
2011

The primary objective of this study is to investigate the physical environmental factors influencing bicyclists‟ perception of comfort on physically separated bicycle paths and on-street bicycle lanes. We also look extensively at comparing the perception of comfort and the contributing factors between the two facility types. Field investigations were conducted at 43 segments on bicycle facilities in the metropolitan area of Nanjing, China. Bicyclists‟ perception of comfort and various environmental conditions were collected. We used an ordered probit (OP) model to analyze the data. Data...

Quantifying the Performance of Countermeasures for Collision Concentration Related to Ramp/Freeway Mainline Junctions

Lee, Joon Ho
Chan, Ching-Yao
Ragland, David R.
2009

This study performed before-and-after analyses (comparisons of collisions before and after the construction of auxiliary lanes) on collision rate at nine study sites in California in order to achieve two objectives: (i) to estimate the freeway Crash/Collision Reduction Factor (CRF) for auxiliary lanes, and (ii) to develop design guidelines for the construction of auxiliary lanes. Findings indicate that on average, collision rates decreased by 17.3 percent at nine study sites. The study also found that after construction of auxiliary lanes at two study sites, collision rates increased when...

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

Arnold, Lindsay S.
Flannery, Aimee
Ledbetter, Lauren
Bills, Tierra
Jones, Michael G.
Ragland, David R.
Spautz, Laura
2010

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...

Development of a Variable Speed Limit Strategy Based on Car Following Behaviors for Improving Freeway Safety Under Severe Weathers

Li, Zhibin
Liu, Pan
Li, Ye
Xu, Chengcheng
Yu, Hao
Zhang, Yuanyuan
2014

Severe weather reduces sight distance and increases stopping distance of traveling vehicles. Traffic collisions are likely to occur when vehicles encounter traffic congestions on freeways under severe weathers. The primary objective of this study is to develop a control strategy of variable speed limit (VSL) to improve freeway safety in different types of weather conditions. The control strategy aims to reduce vehicle speeds gradually prior to congestions. A car-following model was used to simulate the behaviors of drivers in different visibility and road adhesion conditions. The...

Centrality Characteristics of Road Network Patterns of Traffic Analysis Zones

Zhang, Yuanyuan
Wang, Xuesong
Zeng, Peng
Chen, Xiaohong
2011

Road network patterns can affect traffic performance, travel behavior, and traffic safety. Thus, a deep understanding of the properties of different network patterns can provide useful guidance for design and improvement of road systems. The aim of this study is to build a relationship between graphical and topological features of road network patterns of traffic analysis zones (TAZ) and, on the basis of this relationship, to offer a measure that can quantitatively distinguish different graphical pattern types. Toward this goal, a topological analysis measure, centrality, is applied to...

Impacts of Pedestrians on Capacity and Delay of Major Street Through Traffic at Two-Way Stop-Controlled Intersections

Yang, Zhao
Zhang, Yuanyuan
Zhu, Renwei
Ye, Xiaofei
Jiang, Xiaohong
2014

This paper aims to estimate the impacts of pedestrians on capacity and average control delay for the major street through traffic at two-way stop-controlled (TWSC) intersections. A procedure was proposed to estimate the expected delay for major street through vehicles based on the pedestrian arrival time and motorist yielding behavior. Field data were collected to calibrate the crucial parameters in the established models. The proposed models were then validated against field measured data. It was found that the calibrated models provided reasonable delay estimates. Based on the...

Driver obesity and the risk of fatal injury during traffic collisions

Rice, Thomas M.
Zhu, Motao
2016

Background Few studies have looked at how obesity affects injury outcomes among vehicle occupants involved in traffic collisions.

Objective To estimate the association of obesity with death risk among drivers of passenger vehicles aged ≥16 and to examine effect modification by driver sex, driver seat belt use, vehicle type and collision type.

Methods We conducted a matched-pair cohort study using data from the Fatality Analysis Reporting System. WHO body mass index (BMI) categories were calculated. Data were analysed using conditional...

Trauma Center-Based Surveillance of Nontraffic Pedestrian Injury among California Children

Rice, Thomas M.
Trent, Roger B.
Bernacki, Kate
Rice, Jennifer K.
Lovette, Bonnie
Hoover, Eileen
Fennell, Janette
Aistrich, Anna Zacher
Wiltsek, Dana
Corman, Ellen
Anderson, Craig L.
Sherck, John
2011

Introduction: Every year in the United States, thousands of young children are injured by passenger vehicles in driveways or parking areas. Little is known about risk factors, and incidence rates are difficult to estimate because ascertainment using police collision reports or media sources is incomplete. This study used surveillance at trauma centers to identify incidents and parent interviews to obtain detailed information on incidents, vehicles, and children.

Methods: Eight California trauma centers conducted surveillance of nontraffic pedestrian collision injury to children aged...

The Effectiveness of Child Restraint Systems for Children Aged 3 Years or Younger During Motor Vehicle Collisions: 1996 to 2005

Rice, Thomas M.
Anderson, Craig L.
2009

Objectives. We estimated the effectiveness of child restraints in preventing death during motor vehicle collisions among children 3 years or younger.

Methods. We conducted a matched cohort study using Fatality Analysis Reporting System data from 1996 to 2005. We estimated death risk ratios using conditional Poisson regression, bootstrapping, multiple imputation, and a sensitivity analysis of misclassification bias. We examined possible effect modification by selected factors.

Results. The estimated death risk ratios comparing child safety seats with...