Data collection

Centrality Characteristics of Road Network Patterns of Traffic Analysis Zones

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

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

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

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

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.

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...

A Methodology for Counting Pedestrians at Intersections: Using Automated Counters to Extrapolate Weekly Volumes from Short Manual Counts

Schneider, Robert J.
Arnold, Lindsay S.
Ragland, David R.

Accurate methods of counting pedestrians are needed to quantify exposure for safety analysis, rank infrastructure improvements and safety programs by priority, evaluate the benefits of pedestrian projects, develop models of pedestrian volumes, and track changes in pedestrian activity over time. However, pedestrian counts are still much less common than motor vehicle counts in most communities. In addition, existing count methodologies are not standardized and rarely provide enough information to extrapolate to weekly, monthly, or annual volumes. This exploratory study presents a...

Household Travel Surveys in Context-Based Approach for Adjusting ITE Trip Generation Rates in Urban Contexts

Clifton, Kelly J.
Currans, Kristina M.
Cutter, April C.
Schneider, Robert J.

With household travel surveys (HTSs) to produce a regional-scale policy model, this research develops a methodology for predicting context-based vehicle-trip reductions applied to ITE’s Trip Generation Handbook at a site-level development. This methodology may be used as a supplement to ITE trip generation rates, providing justification to vehicle-trip reductions based on known contextual vehicle mode splits. With the 2006 HTS of the Puget Sound Regional Council, Washington State, non-home-based trip ends were selected, and common built environment measures were extracted. A clustering...

Pedestrian Crash Risk on Boundary Roadways University Campus Case Study

Schneider, Robert J.
Grembek, Offer
Braughton, Matthew

Prominent pedestrian trip attractors, such as college campuses and major urban parks, are often surrounded by roadways with high volumes of motor vehicle traffic. Although many pedestrians cross busy boundary roadways, relatively little is known about the pedestrian crash risk along these types of facilities. This study quantifies pedestrian crash risk at roadway intersections on the boundary of the University of California, Berkeley, campus during typical spring and fall semester weekdays. Manual pedestrian counts were extrapolated with data from three automated counter locations to...

Developing Safety Management Tools for State Departments of Transportation

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

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....

Drivers, Pedestrians, and Cyclists in California Want Complete Streets: Comparison of Results from Roadway Design Surveys of Pedestrians, Drivers, Bicyclists, and Transit Users in Northern and Southern California

Sanders, Rebecca L.
Griffin, Ashleigh
MacLeod, Kara E.
Cooper, Jill F.

This paper compares findings from two recent surveys on roadway design preferences among pedestrians, drivers, bicyclists, and public transit users along major urban corridors in the metro areas of San Francisco and Los Angeles. Sponsored by the California Department of Transportation (DOT), the research explored design preferences that could increase perceived traffic safety, walkability, bikability, and economic vitality along urban arterials. Results from intercept surveys showed that roadway users desire similar design features along the test corridors, which carry 25,000-40,000...