Robert Puentes, a senior fellow with the Brookings Institution's Metropolitan Policy Program, said roads remain an important component to any state's transportation infrastructure. But declining or stalled travel on state roads, even as the state's population continues to grow, is "unprecedented" historically, he said, and should be a wake-up call for planners.
The trend is too pronounced to be caused simply by the economy, even if the economy is a factor, Puentes said. Unlike driving declines during the 1970s oil crisis, the current declines have been more prolonged and correlate less with the recession, he said. Similar drops occurring in Europe, Canada and developed parts of Asia also indicate that the trend may be here to stay.
"This is definitely real and it's definitely happening, and that's what's new," he said. "This isn't a blip like we saw in the 1970s or other points, where there was a little dip and then we went back to where we were."
Driving habits in Maryland [Poll]
- Weekend MARC train service, beginning Dec. 7
- Study finds majority of teens delay pursuit of driver's licenses
Some big cities already are addressing the trend, Puentes said, citing Washington's expanding bike-share programs and Baltimore's circulator bus routes. But states are behind the curve, he said.
"The drops in driving are dramatic, they're unprecedented, yet we still model our transportation investments on older trends, extrapolating them out without any understanding that things are changing fundamentally," Puentes said.
The Baltimore Metropolitan Council, which analyzes transportation issues on behalf of elected officials in the major jurisdictions that make up the greater Baltimore region, has noticed the shift away from driving among younger people, said Todd Lang, the group's transportation planning director.
Still, driving remains the state's dominant mode of transportation by a huge margin, he said.
A state study shows that the percentage of commuters who drive to work alone slipped to 73.3 percent in 2011 from 75.2 percent in 2003. Over the same period, there were slight increases in those who work from home (3.1 to 4.1 percent); who walk (2 to 2.3 percent); and who bike (0.2 to 0.3 percent).
Hiroyuki Iseki, an assistant professor of urban studies and planning at the University of Maryland, College Park's National Center for Smart Growth, said those numbers may be low but reflect potential.
"As we provide the alternative modes of travel to driving, then more people are inclined to live in particular areas. They seek the public transit service, they seek the bicycle access," Iseki said.
By the numbers
9,646: Per-capita vehicle miles in Maryland in 2011
4.1: Percent decrease in vehicle miles per capita, 2007 to 2011
15: Average percent increase in vehicle miles every five years, 1980 to 2005
0.7: Percent decline in vehicle miles, 2005 to 2010
73.3: Percent of commuters who drove to work alone in 2011
75.2: Percent of commuters who drove to work alone in 2003
9.2: Percent of commuiters who rode public transit in 2011
8.1: Percent of commuters who rode public transit in 2003