Public transit is often viewed by planners and transportation officials as a key strategy for reducing car dependency, easing traffic congestion, and lowering emissions. Every person who opts for transit over driving helps reduce the total miles driven in private vehicles. According to a large national study, however, good transit has a ripple effect on land use and travel behavior. For every mile not driven by transit riders, transit accounts for another six to nine miles not driven among the larger population.
VMT
Moving from LOS to VMT is more complicated than it might seem
Traffic engineers across the U.S. are accustomed to measuring road performance in terms of “level of service,” or LOS. Recognizing its unintended consequences, many transportation professionals and advocates have urged the industry to replace it with something better. However, LOS has become so ingrained in many processes that there is probably no single alternative to its use.
States must step up efforts to reduce harmful carbon emissions
As of last September, 16 states and Puerto Rico approved legislation requiring reductions in greenhouse emissions. The White House also set ambitious goals of cutting emissions by at least 50% below 2005 levels in 2030. They aim to achieve a net-zero economy by 2050. Contributing to 29% of all greenhouse gas emissions in the U.S., the transportation sector is now the top producer and accounts for a growing portion each year. More than half of these emissions (57%) come from personal vehicles such as cars, SUVs, and light-duty trucks. Progress in cutting those emissions has been slow, let alone efforts to measure and track them.
Workers offset their commute travel when working from home
The massive shift to remote work during the pandemic altered the way many offices operate and increased interest in the potential for widespread telecommuting to help reduce traffic, transportation emissions, and other harmful impacts. We have reported several studies, however, that suggest remote work simply lets people drive at different times of day and for purposes other than commuting. A new study backs that finding.
To manage traffic, researchers ask: “Whose miles are these anyway?”
Several states and many local governments are growing more interested in measuring vehicle miles traveled (VMT) as a key indicator of transportation emissions levels and other unwanted impacts. But measuring VMT, especially at the local site level, can be more difficult than it seems. A new study in the Journal of the Planning Association points to data sources, shortcomings, and considerations for measuring VMT in the future.
State DOTs are key players in cutting transportation emissions
Through a combination of carrots and sticks—but mostly carrots—the federal government has encouraged state DOTs to take ambitious steps to lower the environmental impacts of transportation and to invest in more sustainable travel options. Two years into the Bipartisan Infrastructure Law (BIL), notes Adie Tomer at Brookings, it is still hard to know the impacts. Many states are still operating under the status quo. Others, however, including many SSTI partners, are seizing the opportunity to bolster ongoing local sustainability initiatives.
The work commute changed after the pandemic, new data shows
Research continues to shed new light on the post-pandemic changes in travel behavior and access to opportunities. A recent webinar with SSTI and Accessibility Observatory examines the changes in accessibility across the country, while a new study by Replica highlights new commute patterns in two cities. Both analyses show the lasting impacts of the pandemic on peak travel times, giving transportation professionals valuable insights for adapting planning and design in ways that will improve overall access and system performance.
Success driving less
Driving less is one of the keys to reducing greenhouse gas emissions from the transportation sector, and to reducing the number of deaths and serious injuries on our roads. Most states have seen an increase in per capita vehicle miles traveled over the last 25 years. There are exceptions, however, where political action, multimodal investment, or the development of compact neighborhoods acted to pull VMT numbers down, says a new report by the Frontier Group.
Not having to drive would reduce VMT
In one sense, departments of transportation are in the business of making it possible for people to travel less, or to at least spend less time traveling. But choosing to build capacity and reduce delay effectively speeds up drivers rather than shortening the length of their trips—in an era when driving less is acknowledged as a first-order climate change mitigation strategy. A recent article in Planetizen proposes a solution. If efforts were focused more on allowing people to conduct their daily affairs—shopping, banking, working, health care—over the internet or on the phone, the author writes, it might make a dent in vehicle miles traveled (VMT): a reduction that decades of tepid investment in multimodal options have not been able to achieve.
People like being home, and that offers some benefits
Changing travel behavior may be confounding our traditional notions about transportation demand as evidence shows that people were staying home more even before the pandemic. The debate continues as to whether remote and hybrid work schedules lead to less driving overall, or just distribute driving differently throughout the day. Yet scholars are finding that flexible, work-from-home schedules may be associated with people being more active.