Bike commuters wait for the green light at the intersection of 15th and Massachusetts Avenue in Northwest. (Photo by Astrid Riecken For The Washington Post)

Alternative transportation advocates must often find their solace in small numbers. Over the last decade, the combined rate of bicycle commuting in the 50 largest cities in America has increased — to 1 percent. Last year, national public transit ridership increased, too — by 1.1 percent. More people are now walking to work in Boston and Seattle and Sacramento, by small — but statistically significant! — degrees.

So it's within this context that you may celebrate this tiny detail from new 2013 American Community Survey data: The share of Americans who get to work in a private car has declined since 2007, from 86.5 percent in 2007 to 85.8 percent. Yes, that's less than a percentage point, but it's kind of a big deal. As Adie Tomer and Joseph Kane point out over at the Brookings Institution, the share of Americans driving to work is now trending down for the first time in a couple of decades.

The shift is partly attributable to meager gains in cycling, transit and walking commute modes. But also this, from Tomer and Kane:

The biggest gain, however, came from those workers who didn’t technically commute at all. With the help of burgeoning broadband coverage, nearly as many people now work from home as ride public transportation to their jobs.

The slight national decline in car commuting is also being driven by the country's biggest cities, where alternatives are often more feasible. This Brookings map illustrates that about two-thirds of the largest metropolitan areas in the U.S. have seen a growing share of non-car commuters in the last six years.

Metropolitan share of non-car commuters, 2007-2013

Yes, the numbers are small. But the trend is widespread.