When gas prices rise it seems reasonable to expect people to economize by driving less. According to one indicator brought to light by Eno Center for Transportation, gasoline usage in the U.S.—and by extension driving—hit an all-time high during fiscal year 2022. During the same period gas prices were the highest we’ve seen—adjusted for inflation—since the great recession that began in 2008. But the U.S. is swiftly returning to pre-pandemic levels of vehicle miles traveled (VMT), perhaps due to pandemic-era travel patterns and relocations.
VMT
New study finds households with constrained parking drive fewer miles
More studies over the years have shown us that the price and availability of parking has a strong influence on people’s travel choices. A ten-year-old study from New York, for instance, called attention to the influence of parking availability on people’s decision to drive to work. Several years later, I led a study connecting long-term parking growth to citywide increases in car commuting. Now a new study by a cohort of researchers across North America, including myself, makes that connection even clearer by drawing a direct line from residential parking ratios to household VMT.
Partially automated vehicles increase VMT
Numerous studies have raised concerns that self-driving cars could flood our roads with more traffic, as commuters travel longer distances and cars drive themselves in and out of central cities to avoid parking. Fully autonomous vehicles are probably a ways off, giving policymakers time to grapple with the potential impacts, but new research suggests that even common features found in cars today like adaptive cruise control and lane guidance lead to increased vehicle miles traveled.
Millennials aren’t driving as much as previous generations
The consumption choices and lifestyle preferences of Millennials—those born between 1981 and 1996—and their differences from those of the previous generations have repeatedly piqued academic and policy makers’ interests. Although some suggest they might just be slower in adopting previous trends, a recent study from the University of Texas at Austin suggests that they are a generation that prefers to drive about 8-9 percent less than Generation X and Baby Boomers, and that they might continue to drive less as they get older.
Dog owners drive more, but policy and design changes could help lessen the need
We all can identify a walkable neighborhood, whether we live in one or know what we expect to see in one: good sidewalks, connectivity to surrounding areas, and many destinations. But new research suggests those considerations might be significantly different for dog owners. Since more than one third of households own dogs, complexity is thrown into concepts like the “15-minute city” or cities designed for all age groups and abilities.
Perception and psychology may explain why drivers speed when volume is low
Changed travel behavior during the COVID-19 pandemic has reduced congestion and vehicle miles traveled (VMT), even while traffic deaths continue to rise. Evidence shows that open roads, speeding, and other dangerous driving behaviors go hand-in-hand. But what is it about people that leads them to speed and drive dangerously in the first place?
Major roads undercut safety benefits of highly accessible places
In working with transportation agencies across the U.S., our team often faces questions about the role of safety in accessibility analysis. While we know the safety and comfort of streets clearly impacts access for people on foot or bicycle, the effects of accessibility on overall safety haven’t been clear. Fortunately, leading experts in both accessibility and traffic safety recently teamed up to answer this question.
“Spillover” effects reinforce VMT effects from transit and parking subsidies
We know that employer-provided free parking tends to increase auto-commute trips and that employer-provided transit passes tend to reduce auto-commute trips. Research is less clear about the effect on vehicle-miles traveled, however, in part because we don’t know whether or how such employment practices might affect non-work travel. A new paper using travel survey data from the Seattle area, sheds new light on the VMT question.
Researchers look at the transportation future as the country reopens
As the economy recovers from COVID-19, how can we emerge with a better, stronger, and more resilient transportation system? Three recent reports analyzing the impact of the pandemic on transportation and personal attitudes toward transportation may offer some clues.
Teleworking’s hidden environmental costs
Because of the COVID-19 pandemic and subsequent shelter-in-place orders, more Americans are teleworking. This has drastically reduced VMT and air emissions. Policymakers may be tempted to try to encourage teleworking post-COVID-19 in order to keep the traffic down and the air clean. But as we’ve reported before, telework is probably not a great strategy for emissions reduction, due to several rebound effects. Teleworkers tend to live farther from job centers, in lower-density environments, leading to longer, more auto-dependent commutes when they do go into the office, as well as higher levels of non-work VMT.