Public transportation systems

Evidence Rating  
Scientifically Supported
Evidence rating: Scientifically Supported

Strategies with this rating are most likely to make a difference. These strategies have been tested in many robust studies with consistently positive results.

Health Factors  

Public transportation systems include buses, trains, trams, trolleybuses, ferries, or rapid transit (e.g., light rail transit (LRT), bus rapid transit (BRT), or metro services) that are available for use by the general public and run on a scheduled timetable. Community-wide transportation systems are most common in urban areas and are often supported by federal and municipal funds1

What could this strategy improve?

Expected Benefits

Our evidence rating is based on the likelihood of achieving these outcomes:

  • Increased access to public transit

  • Increased use of public transit

Potential Benefits

Our evidence rating is not based on these outcomes, but these benefits may also be possible:

  • Increased physical activity

  • Reduced vehicle miles traveled

  • Reduced emissions

What does the research say about effectiveness? This strategy is rated scientifically supported.

There is strong evidence that introducing or expanding public transportation systems in urban areas increases access to and use of public transit, especially in dense, centralized cities2, 3, 4, 5, 6, 7. Introducing or expanding public transportation systems can also increase physical activity8, 9, 10, particularly when implemented as part of a multi-component land use approach11, and increase access to safe, healthy, convenient, and affordable transportation12, 13.

Introducing new rail lines in urban areas can increase transit use in cities where many commuters drive to a central business district, and significantly reduce trip time for commuters and other travelers3, 4. Model-based research suggests that subsidizing and investing in public transportation infrastructure can also limit urban sprawl, reduce car use, and promote active transit14. Increases in use of public transit may be associated with increases in housing development near suburban rail stations15.

Transit users appear to have higher levels of physical activity than their peers13, 16. Light rail transit (LRT) appears to increase physical activity9, 10, particularly for new riders9. LRT may also reduce body mass index (BMI) and decrease the likelihood of obesity10.

Reducing fares and increasing the frequency and quality of transit service appear to be the most effective ways to increase use of existing public transit systems17, 18. Frequent, reliable service with few transfers may also make public transit more appealing to drivers19 and may increase rider satisfaction20. Real-time bus tracking may modestly increase ridership and revenue2, and improve rider satisfaction2, 21. Distance-based fare reductions may increase ridership among low income households and elderly and minority individuals, who often use public transit to travel shorter distances than wealthier, younger, or white riders22.

Public transportation systems produce significantly lower emissions per passenger mile than private vehicles, especially when operating with full passenger loads23. Introducing or expanding a LRT system can reduce vehicle miles traveled (VMT) and greenhouse gas emissions among households living within half a mile of a LRT station4. Emissions reductions for LRT and bus rail transit (BRT) systems can be affected by local regulations and component technologies24.

Expanding public transportation infrastructure may decrease disparities in access to services, employment, and recreation opportunities for individuals with low incomes, individuals with disabilities, and the elderly25. However, new public transportation stops can make a neighborhood more attractive, leading to increased rents and, potentially, displacement of long-time residents if policies to preserve affordable housing are not in place26.

How could this strategy impact health disparities? This strategy is rated likely to decrease disparities.
Implementation Examples

U.S. transit systems were used for 10.5 billion passenger trips in 2015; buses accounted for roughly half of all passenger trips27. In 2013, just over 55% of U.S. households reported having access to public transportation; access was highest in Northern and Western cities and lowest in Southern cities28.

Many municipalities have introduced or expanded public transportation systems. New York, NY29; San Francisco, CA30; Boston, MA31; Washington, D.C.32; Philadelphia, PA33; Chicago, IL34; Seattle, WA35; Baltimore, MD36; Los Angeles, CA37; and Portland, OR38 are examples of cities with heavily used, multi-faceted systems.

Implementation Resources

ULI Building healthy places - Urban Land Institute (ULI) Building Healthy Places Initiative. Building healthy places toolkit: Strategies for enhancing health in the built environment.

APTA-Transit facts - American Public Transportation Association (APTA). Where Public Transportation Goes Community Grows. Transit facts at a glance.

HPBD - Healthy Places by Design (HPBD). Advances community-led action and proven, place-based strategies to ensure health and wellbeing for all.

TDM-Public transit - TDM Encyclopedia. Public transit improvements. Victoria Transport Policy Institute.

APTA-Resources - American Public Transportation Association (APTA). Research and technical resources.

SRTSNP-Safe routes to healthy foods - Safe Routes to School National Partnership (SRTSNP). Healthy communities: Safe routes to healthy foods.

LHS - Local Housing Solutions (LHS). To enhance local affordability and foster inclusive communities. New York University, Furman Center and Abt Associates, Inc.


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1 US DOT-FTA - US Department of Transportation (US DOT), Federal Transit Administration (FTA). About FTA: Improving public transportation for America’s communities.

2 Brakewood 2015 - Brakewood C, Macfarlane GS, Watkins K. The impact of real-time information on bus ridership in New York City. Transportation Research Part C: Emerging Technologies. 2015;53:59-75.

3 Baum-Snow 2005 - Baum-Snow N, Kahn ME. Effects of urban rail transit expansions: Evidence from sixteen cities, 1970–2000. Brookings-Wharton Papers on Urban Affairs. 2005;(6):147.

4 Boarnet 2013 - Boarnet MG, Hong A, Lee J, et al. The exposition light rail line study: A before-and-after study of the impact of new light rail transit service. University of Southern California. 2013.

5 Cao 2014 - Cao X, Schoner J. The influence of light rail transit on transit use: An exploration of station area residents along the Hiawatha line in Minneapolis. Transportation Research Part A: Policy and Practice. 2014;59:134-143.

6 TRB-Callaghan 2007 - Callaghan L, Vincent W. Preliminary evaluation of metro orange line bus rapid transit project. Transportation Research Record: Journal of the Transportation Research Board. 2007;2034(1):37-44.

7 TRB-Polzin 2003 - Polzin SE, Page OA. Ridership trends of new start rail projects. Transportation Research Circular E-C058: 9th National Light Rail Transit Conference. Transportation Research Board (TRB); 2003.

8 Sener 2016 - Sener IN, Lee RJ, Elgart Z. Potential health implications and health cost reductions of transit-induced physical activity. Journal of Transport & Health. 2016;3(2):133-140.

9 Brown 2015a - Brown BB, Werner CM, Tribby CP, Miller HJ, Smith KR. Transit use, physical activity, and body mass index changes: Objective measures associated with complete street light-rail construction. American Journal of Public Health. 2015;105(7):1468-1474.

10 MacDonald 2010 - MacDonald JM, Stokes RJ, Cohen DA, Kofner A, Ridgeway GK. The effect of light rail transit on body mass index and physical activity. American Journal of Preventive Medicine. 2010;39(2):105-12.

11 CG-Physical activity - The Guide to Community Preventive Services (The Community Guide). Physical activity.

12 CDC-Transportation - Centers for Disease Control and Prevention (CDC). CDC transportation recommendations - brief.

13 Wener 2007 - Wener RE, Evans GW. A morning stroll: Levels of physical activity in car and mass transit commuting. Environment and Behavior. 2007;39(1):62-74.

14 Su 2008 - Su Q, DeSalvo JS. The effect of transportation subsidies on urban sprawl. Journal of Regional Science. 2008;48(3):567-94.

15 Dong 2016 - Dong H. If you build rail transit in suburbs, will development come? Journal of the American Planning Association. 2016;82(4):316-326.

16 Saelens 2014 - Saelens BE, Vernez Moudon A, Kang B, Hurvitz PM, Zhou C. Relation between higher physical activity and public transit use. American Journal of Public Health. 2014;104(5):854-859.

17 Taylor 2013 - Taylor JC, Johnson RK. Farm to school as a strategy to increase children's fruit and vegetable consumption in the United States: Research and recommendations. Nutrition Bulletin. 2013;38(1):70-9.

18 Taylor 2009 - Taylor BD, Miller D, Iseki H, Fink C. Nature and/or nurture? Analyzing the determinants of transit ridership across US urbanized areas. Transportation Research Part A: Policy and Practice. 2009;43(1):60-77.

19 Chakrabarti 2017 - Chakrabarti S. How can public transit get people out of their cars? An analysis of transit mode choice for commute trips in Los Angeles. Transport Policy. 2017;54:80-89.

20 Wan 2016 - Wan D, Kamga C, Liu J, Sugiura A, Beaton EB. Rider perception of a “light” Bus Rapid Transit system - The New York City Select Bus Service. Transport Policy. 2016;49:41-55.

21 Brakewood 2014 - Brakewood C, Barbeau S, Watkins K. An experiment evaluating the impacts of real-time transit information on bus riders in Tampa, Florida. Transportation Research Part A: Policy and Practice. 2014;69:409-422.

22 Farber 2014 - Farber S, Bartholomew K, Li X, Páez A, Nurul Habib KM. Assessing social equity in distance based transit fares using a model of travel behavior. Transportation Research Part A: Policy and Practice. 2014;67:291-303.

23 US DOT-FTA Transit and climate - US Department of Transportation (US DOT), Federal Transit Administration (FTA). Public transportation's role in responding to climate change. 2010.

24 TRB-Puchalsky 2005 - Puchalsky CM. Comparison of emissions from light rail transit and bus rapid transit. Transportation Research Record: Journal of the Transportation Research Board. 2005;1927(1):31-37.

25 CDC-Active living strategies 2013 - Centers for Disease Control and Prevention (CDC). A practitioner's guide for advancing health equity, community strategies for preventing chronic disease: Active living strategies. Atlanta: US Department of Health and Human Services (US DHHS); 2013.

26 MAPC-Displacement - Metropolitan Area Planning Council (MAPC) Massachusetts. Dimensions of Displacement: Baseline data for managing neighborhood change in Somerville's Green Line Corridor. 2014.

27 ASCE-2021 Report card - American Society of Civil Engineers (ASCE). 2021 Infrastructure report card: Transit report.

28 ASCE-2013 Report card - American Society of Civil Engineers (ASCE). 2013 Report card for America’s infrastructure findings. 2013.

29 NYC MTA - New York City Metropolitan Transportation Authority (NYC MTA). Transit information.

30 SF MTA - San Francisco Municipal Transportation Agency (SF MTA). Transportation choices.

31 MBTA - Massachusetts Bay Transportation Authority (MBTA). Transit information.

32 WMATA - Washington Metropolitan Area Transit Authority (WMATA). Transit information.

33 SEPTA - Southeastern Pennsylvania Transportation Authority (SEPTA). Transit information.

34 CTA - Chicago Transit Authority (CTA). Travel info.

35 Seattle Transit - City of Seattle. Transit.

36 Maryland MTA - Maryland Department of Transportation Transit Administration (Maryland MTA). Transit information.

37 LA Metro - Los Angeles Metro (LA Metro). Transit information.

38 TriMet - TriMet. TriMet provides bus, light rail, and commuter rail transit services in the Portland, Oregon metro area.

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