In 2004, the American Highway Users Alliance dubbed the Katy Freeway in Houston, Texas, the second-most congested freeway in America, squandering 25 million hours of commuters’ lives every year.
Texas’ solution? Go big. Today, the freeway spans a whopping 23 lanes, and claims the title to the widest highway in the world. The AHUA applauded the “fixed” bottleneck in 2015.
Only problem: has five ideas—and one grave warning.
- Ramp meters
Traffic slows exponentially—a small addition of cars can lead to a lot more congestion. But it also means removing a small amount of cars from the road can reduce congestion considerably. Ramp meters do allow one or two cars to enter a highway at a steady rate, keeping traffic speeds flowing at relatively efficient speed. They work: In 2001, Minnesota’s DOT switched off ramp meters to test their effectiveness. They found travel times slowed by 22 percent. “The ramp metering system produces an annual reduction of 2.6 million hours of unexpected delay,” a state report concluded.
- Road pricing
Roads are among the most valuable assets in a city’s portfolio, but few cities price them that way. That’s too bad, since charging drivers to enter certain areas, at certain times, is the single-most effective congestion mitigation strategy cities have at their disclosure. Stockholm decreased travel times by about 40 percent in 2006 by charging drivers just a couple of bucks to enter its city center—London, Singapore, and Copenhagen have seen similar changes with their congestion pricing schemes.
Solving traffic isn’t just about congestion—it’s also about safety. Replacing stop signs or signals with the circular anti-intersections can reduce serious crashes by up to 75 percent—and fatal collisions by up to 90 percent. (There is evidence that roundabouts increase less-serious crashes.) By slowing drivers down, eliminating left turns, and allowing traffic to flow uniformly, roundabouts are an engineering intervention to beat.