Why Expanding Highways Makes Traffic Worse

An anonymous reader quotes a report from Gizmodo: Americans drove 40 percent more miles in 2019 than they did in 1994, according to the U.S. Department of Transportation. More driving means more congested traffic. So to reduce congestion, it makes sense to build more highway lanes so that more cars can fit. Right? Actually, no. A new report from the policy organization Transportation for America shows that doesn't work at all. Between 1993 and 2017, the researchers found that the largest urban areas in the U.S. added 30,511 new lane-miles of roads -- a 42 percent increase. That's a faster rate of growth than population growth, which rose by 32 percent in those cities over the same time period.

But in that 24 year period, traffic congestion didn't drop at all. In fact, it rose by 144 percent even as states spent more than $500 billion on highway capital investments in urbanized areas, and a sizable portion of which went toward highway expansion. That means governments spent billions, and the end result was Americans wasting more time frustrated on the highway, sitting in cars that spew out climate-warming and neighborhood-polluting emissions. That's because when you build more highways, people start driving more and filling up the lanes in a matter of years. From 1993 to 2017, the average person drove 20 percent more miles. Right after a highway is widened, traffic does speed up, and drivers take advantage of that by "switching from other routes, driving further distances or traveling during the busiest time of the day," the report, which looked at federal and state data on traffic and freeway growth, says. "People who had previously avoided congestion -- whether by riding transit, carpooling, traveling during less congested times of day, or foregoing the trip altogether -- start driving on that route more because it has become more convenient."

Read more of this story at Slashdot.