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.

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.

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.

Comparing the car travel of Millennials and Generation X

A new study in the Journal of Planning Education and Research compares the 2017 VMT patterns of Millennials to the 2001 patterns of Generation X. Both groups were at a similar age at the time of the surveys. Previous commentary has proposed that Millennials’ driving patterns would approach those of the previous generation once they aged into child rearing and more fully recovered from the recession of 2008. This study concludes that Millennials are not as likely to drive, even as they reach these traditional milestones.