Awarded New Investigator/Doctoral Dissertation Grant

Safe Streets: GIS Analysis and Countermeasure Evaluation

FOA Number: CE03-027 – New Investigator Training Awards for Injury Research
Project Period: 9/1/2003 – 8/31/2006
Application/Grant Number: 1 R49 CE923138-01
Principal Investigator: Stanley Sciortino, PhD,
San Francisco Department of Public Health,
San Francisco, CA


This project will extend the work of the Departments of Public Health and Parking and Traffic in the County of San Francisco to better understand pedestrian safety and pursue intervention strategies. A systematic analysis of pedestrian injury collision patterns is now needed in addition to pilot studies that evaluate the effectiveness and suitability of countermeasures. This project has three aims:

  • Aim 1: Environmental Hazard Analysis for San Francisco
    Recently collected multi-source pedestrian data (injuries, deaths, volume) and environmental data (traffic signals, traffic volume, street width, etc.) in a Geographic Information System (GIS) will be used to conduct an analysis of pedestrian injury outcomes by location. A Poisson regression analysis will identify environmental risk factors for pedestrian injuries. Pedestrian counts, Census 2000 residence data, or Census employment information will be used as the denominator stratified by age group with an emphasis on the young and the elderly. This analysis will be used to identify intersections, neighborhoods, and traffic corridors that are the most hazardous to pedestrians and the environmental risk factors that constitute those hazards.
  • Aim 2: Evaluation of Countermeasures
    An environmental countermeasure already or soon to be in place in San Francisco will be evaluated. Interventions to be evaluated include the installation of special pedestrian signals. Evaluation will include a before-and-after design for each intervention, where possible, and the use of comparison intersections, selected through the use of geographic models developed in Aim 1. Pedestrian behavioral outcomes and pedestrian-vehicle conflicts, a surrogate measure for collisions, will be used to evaluate the interventions. Actual collision data will be used as well, but may not rise to statistical significance due to the length of this study.
  • Aim 3: Dissemination of Results
    In addition to scientific peer-reviewed publication, dissemination to the local community through community based organizations and city and county government will be ongoing through the Community Health Education Section of the Department of Health.