Global health and climate benefits from walking and cycling infrastructure

A Adam Millard-Ball (Luskin School of Public Affairs, University of California) M Monisha Reginald (Luskin School of Public Affairs, University of California) Y Yasmina Yusuf (Luskin School of Public Affairs, University of California) C Christopher Bian (Google)

Abstract

We use a globally consistent dataset—Google Environmental Insights Explorer—to quantify how urban form and transport infrastructure affect walking and cycling rates in 11,587 cities from 121 countries across six continents. At the city level, population density has the largest effect on walk mode share and has a positive impact on cycling too, as higher densities bring destinations within feasible walk and cycle distances. Density has the strongest effects in wealthier countries where travelers often have more travel choices, while in lower-income places, walking and cycling may be primarily driven by financial constraints. We also find positive effects of bicycle lanes (proxying for a wider array of street design practices) on both walking and cycling. In the median city, each new km of bicycle lanes is associated with ~13,400 additional km yr -1 of bicycle travel. If every city increased the extent of its bicycle network to the level of Copenhagen, Denmark, our simulations indicate reductions in private vehicle emissions of ~6% and health benefits of ~US$435 billion per year.

Article Details

Volume / Issue Vol. 122, Issue 24
Published June 17, 2025
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (4)

A

Adam Millard-Ball

Luskin School of Public Affairs, University of California

M

Monisha Reginald

Luskin School of Public Affairs, University of California

Y

Yasmina Yusuf

Luskin School of Public Affairs, University of California

C

Christopher Bian

Google