Indicator ST.2.b Proportion of households with 1/4 mile access to local bus or rail link
Data Source
Local Bus and Rail Stops data from the San Francisco Municipal Railway. San Francisco Transit Effectiveness Project: About Muni. Accessed online on November 2, 2006: http://www.sftep.com/about.html Household data from Applied Geographic Solutions, Inc. Spring 2007 Update: Current Year Estimates. Methodology available at: http://www.appliedgeographic.com/library.html. Map and table prepared by City and County of San Francisco, Department of Public Health, Environmental Health Section using ArcGIS software.
Table data is presented by planning neighborhood. While planning neighborhoods are larger geographic areas than census tracts, census tracts do not always lie completely within a planning neighborhood. SFDPH used ArcGIS software and a 'centroids within' methodology to convert census blocks to geographic mean center points. We then assigned census blocks to planning neighborhoods based on the spatial location of those geographic mean center points and calculated the planning neighborhood totals for the table.
Detailed information regarding census data, geographic units of analysis, their definitions, and their boundaries can be found in the HDMT at the following links:
http://www.thehdmt.org/etc/Geographic_Units_of_Analysis.pdf
http://www.thehdmt.org/data_map_methods.php
Explanation and Limitations
According to the San Francisco Transit Effectiveness Project, the San Francisco Municipal Railway, also known as "Muni", was founded in 1912 and is the largest public transit system in Northern California and the seventh largest in the nation. The 1,000 vehicles in Muni"s fleet consists of electric trolley coaches, modern light rail vehicles, historic streetcars, buses, alternative fuel vehicles and the famous cable cars. In 1979, the Muni transit network was redesigned as a radial grid system, to provide cross town routes to non-downtown locations and ensure all residential locations were within ¼ mile of a route. The Muni system currently has over 5,000 bus stops and 79 lines with stops every ½ mile. Over the past twenty-five years, demographic and socio-economic shifts in the Bay Area have added to changing the transit needs of San Franciscans. Car ownership and commuting to other counties has increased among city residents at the same time that use of public transit to work has decreased. Increased residential and business development has added to city street congestion. Meanwhile, public transit revenues have not been able to keep pace with the rising costs of fuel, employee wages and benefits, and service start-up costs. In May 2006, the San Francisco Municipal Transit Agency (MTA) and the City"s Controller"s Office launched the Transit Effectiveness Project, an 18-month effort to comprehensively evaluate the existing Muni transit system and recommend ways to attract more riders and make service more effective and economical. On October 21, 2008, the San Francisco Municipal Transportation Agency (SFMTA) Board of Directors voted unanimously to endorse the TEP recommendations for the purpose of initiating any required environmental assessment. Route change implementation will follow any requisite environmental assessments.
Although all households are within ¼ mile of a local bus or rail stop, proximity does not necessarily equal accessibility. Lower income communities tend to rely more heavily on public transportation than higher income communities. Modes of transportation used to access work are dependent upon numerous variables. Among many others, these may include cost, distance, accessibility, perceived and actual safety, weather, pedestrian access and safety, traffic patterns, availability of bicycle lanes and racks, hours of operation, availability of parking, and availability of travel stipends/incentives provided by work or to low income families.
Additional information regarding Muni routes and schedules can be accessed on the SF MTA's website.
Why is this a Community Health Indicator?
Research has found that proximity to public transit helps to determine travel choice.a For normal trips, only 10% of Americans will walk one-half mile. A recent study in King County, WA demonstrated that for every quarter mile increase in distance to transit, the likelihood of using transit fell 16%. One-third of communities near BART stops in the Bay Area used rail to commute to work. Transit use promotes environmental health by reducing air pollution and greenhouse gas emissions from automobiles.- Ewing R, Frank L, Kreutzer R. Understanding the Relationship between Public Health and the Built Environment: A Report to the LEED-ND Core Committee. 2006.