Carbonless Footprints

Similar urban development strategies can benefit both public health and greenhouse gas emissions goals. Increased investment in transit, coupled with increased walkability of local neighborhoods, can lead to a more active, healthier and sustainable future.

Climate change and obesity have both emerged in the past decade as urgent policy mandates. Transportation produces the largest share of U.S. greenhouse gases—much of it generated by routine household travel. Previous research has established associations among transit-oriented neighborhood design, decreases in driving, and increases in walking and bicycling. The evidence suggests that design strategies emphasizing compact development, mixed use, and interconnected street networks may have positive effects for both climate and health. This paper tests that hypothesis by analyzing the relationships between energy used for active and motorized forms of transportation, and by evaluating how modifiable features of the built environment are associated with the ratio between energy used for active versus motorized travel. The analysis relies on data from the Atlanta-based SMARTRAQ travel survey, in which 10,148 participants completed a detailed 2-day travel diary.

Key Findings:

  • Transit accessibility, residential density, and intersection density are positive predictors of walk energy and inverse predictors of motorized energy.
  • A mixed land use pattern that places destinations closer together reduces energy demands for both walking and driving.

This cross-sectional analysis provides clear evidence that urban design strategies can have converging benefits for both public health and climate change.