This post is part of a series on the past, present, and future of commuting in America.
The technology that most profoundly changes US commuting might not be the self-driving car.
It could be the internet.
Already, in many places, traffic engineers see notably reduced congestion on Fridays — a day when many offices let their workers telecommute from home. "I've spoken with people from the Maryland Department of Transportation, and they say there's no question," says Alan Pisarski, author of the Commuting in America report. "On Fridays, you really see a difference in traffic coming down from the suburbs to DC on I-270."
This shift is part of a broader trend: the steady fragmentation of what used to be a relatively uniform pattern of commuting. A few decades ago, the standard commute was for a full-time, 9-to-5 shift. People living in the suburbs mostly drove into the city in the morning and back in the evening.
But as more and more people work flexible hours, part-time jobs, or from home, the flood of commuters that used to fill highways during rush hour is becoming a stream that runs intermittently all day. Most suburban commuters, meanwhile, don't drive into the city — they drive to other suburbs.
Millions of people are now working at home
Census data shows that the percentage of people who work from home every day is rising quickly, more than doubling since 1980. It's still only 4.33 percent of workers, but that's more than 5 million workers — and is more than the number of people who walk or bike to work combined:
About 45 percent of these workers are self-employed (with many working as freelancers or independent contractors), but a growing number of them are employed full-time in the private sector.
These employers aren't letting them stay home because they're suddenly feeling charitable, but rather because technology now allows them to easily ensure employees are actually working — and because doing so can save businesses a lot of money.
"The recession has also made companies more sensitive to operating costs," says Tim Lomax, a transportation researcher at Texas A&M. "If you can get someone to work from their home, where they don't need a parking space or an office, that reduces your cost of doing business."
Millions of others are working alternate schedules
What's more, the census only asks about your normal everyday commute, so its numbers don't include the many people who work from home occasionally, or those with other sorts of alternative schedules.
"More and more, people are working compressed schedules — say, with alternate Fridays off, or one or two days at home per week," Pisarski says. More people also work in fields that allow for varying schedules (like the health-care and service industries) than those that don't (like industry).
Meanwhile, the number of people working part-time has swelled since the start of the recession, rising by 2.1 million between 2005 and 2012. Increasing numbers of people, unable to find full-time work, are also combining multiple part-time jobs.
All these trends have broken up the old, predictable traffic patterns of yore. They're the reason for the reduced traffic on Maryland's I-270 (and many other highways around the country) on Fridays, and they mean that the twice-daily surge of commuters we used to see during rush hour is increasingly being spread out to other parts of the day:
Most suburbanites are no longer commuting into the city
Another dominant pattern being disrupted is geographic. "Our transportation system has basically been designed for radial service — getting people from the suburbs to the city center and back," says Pisarski. "But that's not what's going on now, and it'll be even less so in the future."
Though some people commute from suburb to city, most suburbanites actually commute to other suburb areas within the same metro area. A decent fraction of city dwellers, meanwhile, commute out to the suburbs for work.
This shift began as early as the 1980s. Though many early suburbs were initially designed primarily as residential areas, businesses have increasingly chosen to locate in them for a few different reasons, including lower real estate costs.
Additionally, the rise of households with multiple people working means that many families end up settling in compromise locations, halfway between a pair of distant jobs. This is why an increasing number of people (now about 27 percent of workers) cross county lines while commuting — and why several million people even end up commuting to other metro areas every day.
Increasingly, different cities have different commuting patterns
One final pattern being disrupted is the general uniformity of commuting across the country. It used to be that most US cities were pretty similar — in terms of the modes of transportation people chose, the geographical patterns of commuting that went on, rates of growth, and other variables.
But that's changing. "In some strong urban markets with particular lifestyles and cultures, or better transit — say, Boulder, Colorado, or San Francisco — we're seeing one set of trends," says Steve Polzin, a transportation researcher, "and in a place like Oklahoma City, we're not seeing them at all."
Polzin notes that between the 2000 and 2010 census counts, about a third of the counties nationwide had declining population, while another third grew explosively — accounting for 90 percent of the country's population growth.
For the planners trying to figure out the highways, transit, and other infrastructure projects we'll need in the future, this presents a big challenge. It means that even within the same region, one city might have a lack of jobs and lots of underused infrastructure, while another might have a shortage of infrastructure and plenty of jobs.
As Pisarski puts it, "It's harder and harder to talk about 'national trends' in commuting."