More highways, more congestion

By Eric Sundquist

In pursuit of congestion relief, the United States added 63 percent more urban freeway lane-miles between 1990 and 2017. That rate far outstripped the 46 percent growth in urban population.

It didn’t work. As widely reported last month, the Texas Transportation Institute’s Urban Mobility Report has returned after a five-year hiatus. It finds that:

Congestion, by every measure, has increased substantially over the 36 years covered in this report. Almost all regions have worse congestion than before the 2008 economic recession that caused a drop in traffic problems. Traffic problems as measured by per-commuter measures are worse than a decade ago, and because there are so many more commuters, and more congestion during off-peak hours, total delay has increased by two billion hours. The total congestion cost has also risen with more wasted hours, greater fuel consumption and more trucks stuck in stop-and-go traffic.

Critics point to conceptual and methodological issues in the Urban Mobility Report, not the least of which is that a congestion-delay calculation assumes that a 50-minute trip to a destination at free-flow is better than a 5-minute trip to a destination.

Still, congestion is clearly still with us, despite a Herculean effort to fix the problem with new lane-miles (as well as smaller efforts around transit, operations, and policy). The failure of new capacity to reduce congestion—or its arguably worsening effect—is consistent with the decades of research around induced demand, which suggests we should look to solutions other than highway capacity, an approach taken in MassDOT’s recent report on the topic.