Progress in public health and transportation: Changes in state- and regional-level prevalence of active commuting to work from 2005 – 2017
Background
Increasing commutes made by walking, riding a bicycle, or public transportation (active commuting) can increase physical activity and reduce congestion and is a shared goal of public health and transportation (1,2). State public health and transportation agencies can work together to implement environmental and policy strategies (e.g., Complete Streets) to support active commuting (3). Since 2005, the American Community Survey (ACS) has provided consistent, annual journey to work data for the nation and states, but state- and regional-level changes in the combined prevalence of walking, bicycling, or taking transit to work since 2005 have not been reported.

Purpose
To examine changes in the prevalence of active commuting to work from 2005 to 2017, stratified by state and Census region.

Methods
ACS is a representative survey of approximately 1% of U.S. households, administered by the U.S. Census Bureau (4). Employed ACS participants aged ≥16 years (2005 n=1.3 million, 2017 n=1.5 million) reported the primary mode of transportation to work in the past week. Participants who reported walking, biking, or taking public transit (bus, streetcar, subway, railroad, ferryboat) were classified as active commuters. Prevalence of active commuting to work for the first (2005) and last (2017) ACS cycles was estimated by Census region and state; territories and Washington, DC were not included. Differences between years were tested with adjusted Wald tests and deemed statistically significant at p<0.05. All analyses followed ACS guidelines for weighting and variance estimation.

Results
From 2005 to 2017, the prevalence of active commuting to work increased in the Northeast from 17.4% (95% confidence interval [CI] 17.2-17.6) to 19.6% (19.4-19.7), including increases in CT (2005 to 2017: 6.9% to 7.7%), MA (12.4% to 16.1%), NJ (13.6% to 15.2%), NY (31.8% to 35.0%), and PA (8.9% to 9.6%), and a decrease in NH (4.1% to 3.1%). The prevalence increased in the South from 3.7% (95% CI: 3.6-3.8) to 3.9% (3.8-3.9), including increases in DE (2005 to 2017: 3.8% to 5.2%), KY (2.6% to 3.5%), NC (2.5% to 2.9%), SC (2.4% to 2.8%), and VA (5.5% to 7.3%), and a decrease in LA (4.0% to 3.3%).

The prevalence increased in the Midwest from 5.5% (95% CI: 5.4-5.6) to 5.9% (5.8-6.0), including increases in IL (2005 to 2017: 11.3% to 13.1%) and MI (3.2% to 4.1%). The prevalence increased in the West from 7.2% (95% CI: 7.1-7.4) to 7.9% (7.8-8.0), including increases in CA (2005 to 2017: 7.9% to 8.4%), CO (6.4% to 7.0%), HI (9.9% to 12.3%), OR (9.0% to 10.3%), and WA (8.2% to 10.5%), and a decrease in ID (4.8% to 3.7%). Changes in the states not listed above did not reach statistical significance.

Conclusions
Since 2005, the prevalence of active commuting to work has increased in all four Census regions and 17 states. However, the prevalence remains low (≤5%) in more than half of U.S. states, particularly in the South and Midwest. Public health and transportation agencies at multiple levels of government can work collaboratively to implement policy, systems, and environmental strategies to increase active commuting.

Presenter: Geoffrey Whitfield
Agency Affiliation: Centers for Disease Control and Prevention

Presenter Biographical Statement: Dr. Geoffrey Whitfield is an epidemiologist at the Physical Activity and Health Branch in the Division of Nutrition, Physical Activity, and Obesity at CDC in Atlanta, Georgia. He holds a master’s degree in exercise physiology and a PhD in epidemiology from the University of Texas System. His research interests include the health impacts of transportation-related physical activity, the environments that support walking and bicycling, and public health surveillance of physical activity and environmental supports of activity.