Indicator TR.1.b Trips by non-auto mode


Descriptive Title: Proportion of trips made by walking, biking, or public transit

Why Is This An Indicator Of Health and Sustainability?

Environments that support walking, biking and transit trips as an alternative to driving have multiple potential positive health impacts.  Quality, safe pedestrian and bicycle environments support a decreased risk of motor vehicle collisions and an increase in physical activity and social cohesion with benefits including the prevention of obesity, diabetes, and heart disease as well as stress reduction and mental health improvements that promote individual and community health.  Environments that encourage walking and biking while discouraging driving can further reduce traffic-related noise and air pollution – associated with cardiovascular and respiratory diseases, premature death, and lung function changes especially in children and people with lung diseases such as asthma.a

Public transportation links people to jobs, goods and services, and also helps communities achieve public health benefits such as increased physical activity via walking to transit, reduced pollution, and reduced fatalities and injuries.  Walk-to-transit trips account for 16% of all recorded walking trips based on an analysis of U.S. travel survey data; these trips tend to be longer than average walking trips.b The lifetime odds of dying as a car driver or passenger are 1 in 303 – approximately 300 times the odds of dying as a bus occupant (1 in 89,945) and 750 times the odds of dying as a train occupant (1 in 227,509).c 

Public transit can also provide an equitable transportation option and improve mobility, independent of age, ability, income or race.d  In California, transportation costs are the third largest expense behind housing and food among low-income households—roughly the poorest 25%.e  Walking and biking are relatively inexpensive forms of transportation when they are able to provide access for residents to nearby goods, services, or jobs.   Ensuring adequate non-auto trip opportunities – including via public transit, walking or cycling - with matching infrastructure, particularly in lower income communities, could increase non-auto trips and support multiple health benefits in communities often disproportionately burdened with poorer health outcomes.


Using SF CHAMP 4.3.0 data for 2011, the trips made by transit and non-motorized person trips were summed by transportation district and divided by the total number of trips in San Francisco’s 12 transportation districts, and then mapped.


Data is from the SFCTA’s travel forecasting model, SF CHAMP 4.3.0 data.  While the model is internationally regarded as a sophisticated travel forecasting approach which provides the best available estimates, its outputs are not precise predictions and the district-level estimates presented in the above map and table have not been validated. 

Transportation mode choice is influenced by multiple factors including cost, distance, accessibility, perceived and actual safety, weather, pedestrian safety, traffic patterns, availability of bicycle lanes, availability of transit routes, hours of operation, availability of parking, and availability of travel stipends/incentives provided by work or to low income families.

  1. PolicyLink, Prevention Institute, the Convergence Partnership. 2009. Healthy, Equitable Transportation Policy, Recommendations and Research. Available at:

  2. Weinstein A, Schimek P. 2005. How much do Americans walk? an analysis of the 2001 NHTS. Presented at: Transportation Research Board Annual Meeting; January 9-13, 2005, Washington, DC.

  3. National Safety Council. 2011.  Injury Facts 2011 Edition.  Available at:

  4. American Public Health Association. 2012.  Public Transportation: A Link to Better Health and Equity. Washington, DC. (Accessed March 19, 2012:

  5. Public Policy Institute of California. 2004. Transportation Spending by Low-Income California Households: Lessons for the San Francisco Bay Area. Available at: