Related Links

"PedSafe Phase I Final Report," December 15, 2003, an intensive pedestrian safety engineering study with associated explanation of modeling techniques and use of geograpic information systems.

 San Francisco PedSafe, a TSC Web site overview of the San Francisco PedSafe Project.

"Mean Streets 2004: How Far Have We Come?" Downloadable Surface Transportation Policy Project report on pedestrian safety statistics and case studies of safety programs.

Toward "Healthier" (Safer) Urban Pedestrianism

Four-Year San Francisco PedSafe Project Now in Evaluation Phase  

What has emerged out of the four-year San Francisco PedSafe: Assessing and Deploying Innovative Means to Enhance Pedestrian Safety project is one of the more comprehensive pictures of the causes of pedestrian injury in a city.

Undertaken with the San Francisco Department of Parking and Traffic and funded by the Federal Highway Administration (FHWA), the project involved the analysis of more than 12,000 police accident reports and hospital discharge records that were combined with a GIS analysis and modeling software. 

Over the course of the project, researchers have identified problem areas, recommended countermeasures, and conducted citizen outreach in the hopes of raising safety awareness in neighborhoods most affected.

Their analysis of pedestrian injury and fatality records helped them create maps showing where pedestrian-vehicle conflicts are most likely to occur and the rate and type of injury. Center researchers also used new modeling software to analyze the data and give a more nuanced description of causes and effectiveness of potential countermeasures.  
 

San Francisco: a "Good" Place for a Study

San Francisco won a grant from the Federal Highway Administration in part because its pedestrian injury rates are high, even accounting for the high rate of pedestrian activity in the city. It ranks fourth in injuries per capita in cities with populations over 500,000, and is the only California city in the top five. (This ranking comes from the 2004 edition of “Mean Streets,” compiled by the Surface Transportation Policy Project, a non-profit advocate for automobile alternatives, containing the ranks of major cities in relation to pedestrian injuries per capita.)

As TSC researchers explained in their December 2003 report in Phase I, the city "is a particularly good setting to test such a comprehensive program because of its diversity, challenging environments, reliance on walking and public transit, and demonstrated commitment to improving pedestrian safety…. The City has significant populations of different minority groups, a large number of immigrants (presenting language and cultural challenges to safety efforts), and neighborhoods spanning the socioeconomic range….The numerous hills, skewed intersections, and transit stations and boarding islands all present safety issues."

Researchers found that more than half of the primary factors in collisions were driver factors, and most of those were driver violations of pedestrian rights of way, followed by excess driving speed. About 41 percent of the primary collision factors were pedestrian-based, the most common being failure to yield while crossing mid-block and walking against a signal. "This suggests that efforts aimed at both groups will be productive," noted TSC Director David Ragland.

(Click on image to go to larger view.) By mapping the 12,000-plus pedestrian injury collisions, researchers were able to rank the city’s 125 most dangerous intersections. Twenty were located in the vicinity of the greater downtown area and along major arterials like Mission St., South Van Ness Ave. and Divisadero St. Researchers used FHWA analytical tools to focus on seven high-risk zones that encompassed 48 of the 125 worst intersections. The zones were: South of Market, North Mission, Chinatown, Outer Mission, Geary Blvd., Japantown, and Upper Market.

Data for each zone were then collected to show crash patterns, type and number of traffic control devices, and demographics including pedestrian activity, land use, zoning, and other facets.

Field observations were carried out at three intersections per zone, yielding 21 primary study intersections where researchers were deployed to determine pedestrian volumes, driver and pedestrian compliance with signals, and note the frequency of crashes and, most often, proxies crashes like pedestrians running across the street or dashing back to the curb in an aborted crossing. The physical features of each of the intersections were recorded and fed into a software program to create crash diagrams, which provide pedestrian data so detailed that pedestrian injury rates can be correlated to time of day, type of weather, time of year, and other indices for the whole city.

This information was used to design intersection-specific countermeasures like countdown versions of pedestrian signals, ladder-style striped crosswalks, brightly colored pedestrian crossing warning signs, scrambles (where pedestrians are given an exclusive, four-way phase—see story on Oakland's pedestrian scramble in this issue) in-pavement crosswalk lighting, and impactable yield-to-pedestrians signs.

The evaluation phase will continue into 2007, at which time TSC researchers will measure the effectiveness of a combination of countermeasures. In addition, they will help the city to develop an outreach program for schools and senior centers to pass along basic safety tips and educate people about the new measures.

Related Links

"PedSafe Phase I Final Report," December 15, 2003, an intensive pedestrian safety engineering study with associated explanation of modeling techniques and use of geograpic information systems.

 San Francisco PedSafe, a TSC Web site overview of the San Francisco PedSafe Project.

"Mean Streets 2004: How Far Have We Come?" Downloadable Surface Transportation Policy Project report on pedestrian safety statistics and case studies of safety programs.

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