“It’s about density. It’s about zoning. And about sort of the typical division … between the urban environment and the suburban environment, particularly in the U.S.,” said Martin Morzynski, senior vice president of marketing at StreetLight Data, explaining some of the broad takeaways from its June 2025 Transportation Mode Share Report. Findings include the shockingly meager share of bike trips, compared to car and walking trips, in U.S. cities of all sizes.
The study does not include transit trips but has the understanding that a vast majority of transit trips include a walking and, possibly, a biking trip.
“Both [walking and biking] are impacted by the availability of transit, because transit makes it possible to get to your destination on a trip that could involve both walking and transit,” Morzynski said. “The availability of transit will impact this data. The availability of access to transit.”
What is clear is that 9 out of 10 U.S. counties with the highest levels of active transportation — walking and biking — have a population density of at least 4,000 people per square mile. For example, New York County, N.Y., which includes Manhattan, has the highest level of active transportation, where 48 percent of trips are taken via walking, 11 percent are taken by bicycle and 41 percent in an auto.
The report analyzed trips occurring in 646 counties, which are the U.S. counties with a population density of at least 150 people per square mile. To qualify as a trip, the distance traveled has to be at least 300 meters, or just under 1,000 feet.
There is an “indisputable correlation between density of cities, and their walkability,” Morzynski said. “We all know that.”
Biking accounted for 5 percent or more of trips in only six counties, all of them in the Northeast, with the exception of San Francisco County in California. Walking trips are much more common, though they still pale compared to trips taken in vehicles.
Given the growth — and publicity — of urban features like bike lanes, bike-share operations and other aspects of micromobility, “the reality is, even in New York City, where there’s a lot of bike ridership … bike trips in New York make up 11 percent of total, while walking makes up 48 percent of total,” Morzynski said.
Increasingly, walking and biking are seen as key pieces of the overall transportation ecosystem in a region spurring the development of infrastructure like bike lanes, mobility hubs and the advancement of micromobility programs for sharable bikes and scooters. And indeed, public transit is viewed as an enabler of active transportation, since if it were not an option, a number of biking and walking trips would simply become car trips, Morzynski said.
Shared micromobility “should complement one another,” Camille Boggan, program manager for policy and practice at the National Association of City Transportation Officials, said.
“But also multiple ways to connect to mass transit,” she said during a June 10 webinar organized by the North American Bikeshare and Scootershare Association. “So that people can use that last-mile option to get to their home or the grocery store.”
Increasing density can accomplish more than converting car trips to walking or biking. It can also help to solve housing shortages, urbanists have said. Researchers with the Urban Institute have cited studies showing increased density, coupled with reduced parking requirements, help to bring down the cost of housing, while also making smarter use of transit investments.
“The fact that we have regional transportation infrastructure, and regional housing needs, suggest that we need to be thinking regionally about how to plan for the future and how to develop land-use planning that works,” Yonah Freemark, principal research associate at the Urban Institute, and one of the authors of the report Making Room for Housing Near Transit: Zoning’s Promise and Barriers, told Government Technology in January 2023.
