Pedestrian Injury Forecasting Model

Description

The Vehicle-Pedestrian Injury Collision Model predicts change in the number of collisions resulting in pedestrian injury or death associated with area-level changes in street, land use and population characteristics due to new development or transportation system changes. SFDPH uses this model to inform the need for pedestrian safety mitigations and improvements in the course of land use and transportation planning, to prevent people from being injured or killed by motor vehicles while walking on San Francisco streets. Significant predictors (census-tract level variables) in the current model are:

	Traffic volume	Employee population
	Arterial streets (%, without MUNI transit)	Resident population
	Neighborhood commercial areas (%, land area)	Below poverty level (%, population)
	Land area (square miles)	Age 65 and older (%, population)

Background and Development

Primary preventable predictors of vehicle-pedestrian injury collisions are environmental, including: traffic volume, higher vehicle speeds, pedestrian volume, and intersection and street design factors. To achieve safe, walkable communities, planning professionals need practical tools to assess and mitigate the impact of land use and development plans and projects on pedestrian safety, including vehicle-pedestrian collisions. Currently, the tools available to evaluate the impacts of land use planning on pedestrian safety conditions are limited to existing conditions assessments of collisions or qualitative analyses of the pedestrian environment.

Vehicle-pedestrian injury collisions: San Francisco, California census tracts (2001–2005)

SFDPH began developing this multivariate model to understand how changes in traffic and other environmental factors impacted by development decisions in SF predict vehicle-pedestrian injury collisions. The model was developed in collaboration with the UC Berkeley School of Public Health and sought input from health, planning, and transportation professionals, and community advocates for pedestrian safety – both individually and through presentations at City staff and task force meetings, professional conferences, and academic settings – throughout the process.

SFDPH published the pedestrian injury model findings in January 2009 in the professional scientific journal Accident Analysis & Prevention and is now writing a second manuscript detailing the practical application of the model to the Eastern Neighborhoods Area Plans in San Francisco.

Collaborations/Constituencies Involved

SFDPH researchers developed the Vehicle-Pedestrian Injury Collision Model in collaboration with Edmund Seto, a UC Berkeley School of Public Health researcher and lecturer – drawing on traffic data generated from an on-going collaboration regarding the health impacts of traffic and transportation planning decisions.

As detailed above, constituencies for this work include public health, transportation, and planning professionals that could apply the model to anticipate the need for improvements, as well as pedestrian safety and community organizations that could advocate for its application to predict health impacts of planning decisions. SFDPH continues to engage with these constituencies regarding both our findings and potential practical applications to predict vehicle-pedestrian injury collisions based on area-level changes impacted by City planning decisions, including Congestion Pricing policy.

Relevance to Health and Health Equity

Walking, both as an alternative to driving and as a leisure activity, can be beneficial for human health by reducing the risk of motor vehicle collisions, reducing motor vehicle-related noise and air pollution, and increasing physical activity and social cohesion.

In San Francisco, neighborhoods with some of the lowest proportions of households owning cars are disproportionately burdened by streets with high traffic volumes, posing serious hazards to pedestrians. Those neighborhoods also have some of the highest concentrations of poverty and people dependent on walking or public transportation as their primary mode of travel.

Walking and public transit, as opposed to driving, are sustainable travel modes – and can be supported by safe environments that promote those behaviors. Land use and transportation planning processes provide an opportunity to assess pedestrian safety conditions for current and future San Francisco residents and workers, and to intervene to improve the pedestrian environment and support safe, sustainable transportation modes – provided there are tools to conduct these assessments.

Applications and Policy Targets

The main aim of the application of the San Francisco Vehicle-Pedestrian Injury Collision Model is to inform the need for pedestrian safety mitigations and improvements in the course of land use and transportation planning. Potential area-level interventions that improve pedestrian safety include planning and design decisions that reduce traffic volumes, speeds, and the need to drive, while promoting more walkable, safe environments including: transportation-land use planning coordination, transportation demand management measures, traffic calming, and street and intersection engineering countermeasures and amenities. The Victoria Transport Policy Institute’s online Transportation Demand Management Encyclopedia provides detailed information regarding these strategies.

SFDPH is currently using the model to assess potential impacts of Congestion Pricing policy being studied by the SF County Transportation Authority. SFDPH also used the model to analyze the impact of the Eastern Neighborhoods plans using estimated changes in resident population and traffic volume from the SF Planning Department in a technical review draft Impacts of Urban Land Use Development on Pedestrian-Motor Vehicle Collisions: An Application of the San Francisco Pedestrian Injury Model to Five Neighborhood Plans. The plans are expected to produce both a modest increase in local area traffic volume and a more substantial increase in the resident population. The model predicted that the plans’ implementation will result in increases in five-year pedestrian injury collision totals - by approximately 17% overall, or over 30 additional pedestrian injury collisions on those streets each year. SFDPH’s analyses were included in the Pedestrian Safety Assessment of the Eastern Neighborhoods Environmental Impact Assessment.

Contact Information

Please e-mail Megan Wier or call 415-252-3972 for additional information regarding model development and application.

Public Health Analysis of Road Closures at Golden Gate Park: Motor Vehicle Collisions and Injuries

On Tuesday April 17, 2007, The San Francisco Board of Supervisors voted 9-2 to a approve a proposal to close a section of Golden Gate Park to vehicle traffic. The proposal establishes new car-free space in the Park on Saturdays on JFK Drive between Tea Garden Dr. (near 8th Ave.) and Transverse Dr. for six months each year, April through September, beginning Saturday, May 26th, Memorial Day weekend.

This report documents a comparative analysis of motor vehicle collisions resulting in pedestrian or bicyclist injuries in and around Golden Gate Park on Saturdays and Sundays.