Walking to public transit helps achieve physical activity recommendations
Background: Guidelines for physical activity recommend that adults achieve at least 150 minutes of aerobic physical activity per week. However, only half of U.S. adults report obtaining sufficient levels of physical activity. Public transportation systems may encourage and support physical activity as users commonly begin and end transit trips with walking. Previous research showed that transit-associated walking increased from 2001 to 2009, but it is unknown whether this increase has been sustained.

Objective: To assess sociodemographic correlates and temporal trends in transit-associated walking in the U.S. from 2001 to 2017 using data from the National Household Travel Survey (NHTS), a nationally representative survey of travel behaviors.

Methods: Using the 2017 NHTS, we compared the weighted proportion of transit walkers to the total NHTS population by household income, age, education level, race/ethnicity, gender, urban size, car ownership, worker status, online delivery use, and use of a rideshare app (e.g., Uber). Multivariable logistic regression was used to determine predictors of achieving at least 30 minutes of walk time per day solely by walking to and from transit. We evaluated trends in the weighted median total walking time to and from transit using the 2001, 2009, and 2017 NHTS. Survey analysis procedures were used to account for unequal probability of selection and nonresponse.

Results: In the 2017 NHTS, transit walkers (unweighted n=4596) tended to be younger, from households earning less than $25,000/year, without a car, located in an MSA of at least 3 million persons, and served by a rail system compared to the general population (unweighted n=230,592). A greater proportion of transit walkers was non-Hispanic black, Asian/Pacific Islander, and Hispanic. After adjusting for income, age, education, race/ethnicity, and sex, the odds of obtaining at least 30 minutes of daily walk time was 61% higher among transit users with access to a rail system compared to those without (OR: 1.61; 95% CI: 1.30, 1.99; p-value <0.001) and 34% lower among transit users who made online purchases in the past 30 days (OR: 0.66; 95% CI: 0.52, 0.85; p-value = 0.002). From 2001 through 2017, median daily transit associated walk time remained consistent (2001: 19 minutes [95% CI: 17.5, 20.5]; 2017: 20 minutes (95% CI:
18.5, 21.5]). The proportion of transit walkers obtaining at least 30 minutes of daily walk time did not change substantially over time (2001: 28.9% [95% CI: 26.4, 31.4]; 2017: 30.3% [95% CI: 28.2, 32.4]). Discretionary travel (shopping, family/personal business, social/recreational, or medical/dental trips) comprised roughly half of total travel trips among transit walkers over the study period. Between 2001 and 2017, the proportion of discretionary travel due to shopping declined from 35.0% to 31.0%.

Conclusion: Using public transit contributes to physical activity, and literature supporting this finding, as well as other health benefits (e.g., reduced air pollution, traffic crashes) is growing. Continued monitoring of transit-associated walking using NHTS is important, given that technological advancements (e.g., shared mobility, autonomous vehicles) and the growth of online retail may impact transit use and associated physical activity in the future.

Presenter: Vi Le
Agency Affiliation: University of Washington

Presenter Biographical Statement: [biography]