A recent blog from Twin Cities Sidewalks highlights growing evidence that vehicle miles may have peaked. If the right policies are put in place, vehicle miles can go down even as the population and economy rises. The graph dramatically shows the historical trends of vehicle miles traveled in the US and how they have changed in recent years. Young adults, who may set the direction for generations to come, are on a steep downward trajectory. After that graph came out, the Federal Highway Administration reported that only 67 percent of 16-to-24 year olds had driver's licenses in 2011, the lowest level since statistics have been kept. For cities, where more alternative transportation options are available, the trend is potentially stronger: from 2005 to 2009, as the population of Washington, DC, grew by 15,000, car registrations in the District dropped by 15,000, according to Jeff Speck in Walkable City. This adds impetus to getting rid of policies like minimum parking requirements (why turn America into even more of a parking lot than it already is?). Let's, instead, go with the flow and spend more on walking, biking, and mass transit, and less on expanding highway capacity for cars that likely will not be there.
A study by the universities of Washington and Maryland researchers adds further weight to the notion — now confirmed in many studies — that smart growth (higher density, mixed-use, walkable urban form) significantly reduces vehicle miles traveled (VMT). The study, published in Transport and Land Use, emphasizes that reducing block sizes is a more important factor than density and mixed-use in some cases. The study looked at subareas of the Washington DC, Seattle, Baltimore, Richmond VA, and Norfolk VA metro areas. The Virginia metro areas are smaller than the others, and the subareas studied there are lower-density and more sprawling (as measured by block size). In Washington, Seattle, and Baltimore, where the urban pattern is well established, an increase in density and mixed-use had a greater effect on VMT. "Reducing the average block size turns out to be the most effective in the Virginia case with the largest existing average block size," note the authors of the study "How built environment affects travel behavior: A comparative analysis of the connections between land use and vehicle miles traveled in US cities."
Adjusted for population, US driving has taken a historic downward turn, as shown in a new graph by Business Insider (see above). Total US miles driven have declined only slightly since the peak in 2007, and they are up a little this year from last. Some may view the decline as a blip in an overall upward trend, but adjusting for population gives a different picture. US drivers are now back where they were in 1995 — more than 17 years ago. We are still driving nearly 50 percent more, individually, than we were in 1971, so there are plenty of cars on the road (and the number of drivers has risen as well). But the per person driving trend begs the question — to the extend that people are driving less of late, how are they getting around? Transit ridership is near historic highs, which probably means that people are walking more as well (most transit trips begin and end with a walk, and transit service is often located in walkable places). Bicycling is also on the rise in many cities and towns. Another question: Will more transportation dollars flow to alternative modes, creating a positive feedback loop?
The Economist came out with a great report on why demographic trends mean that "peak driving" is likely here to stay in the US. Per capita vehicle miles driven peaked in 2007 at something over 28 miles per day. Even with 12 straight quarters of economic growth, driving per capita has stayed below that high-water mark. Young people are driving significantly less than they did a generation ago (see graph above, spotted on Streetsblog). The generation that came of age in the 1950s and early 1960s, which drove more than any other, is now in retirement age. They are taking shorter trips and are being replaced by Millennials who prefer to live in the city, take transit, and walk. Rising gasoline prices — up six times the rate of inflation since 1998 — are also a factor.
A 10 percent rise in smart growth leads to a 20 percent drop in vehicle miles traveled (VMT), according to a paper by Dr. Sudip Chattopadhyay of San Francisco State University — published in the B.E. Journal of Economic Analysis and Policy. Chattopadhyay looked at 18 US metro areas to examine what program would have a bigger impact — raising fuel taxes or implementing smart growth policies. Smart growth was measured in residential and job density and per capita expenditures on transit. Raising the cost of driving by 10 percent would reduce VMT by 18 percent, the research found. Smart growth policies could have a significant impact, the paper said. "If mid-sized California cities like Modesto, Fresno, and Bakersfield had similar density and transit amenities as some of the state’s larger cities — the Bay Area and Los Angeles — they could expect to see a 55 percent reduction in per household driving activity, or about 5,238 miles per year," reports Streetsblog.