Expanding highways and building more roads actually makes traffic worse - Curbed
It’s a great time to be a road builder in the United States, and a terrible time to be a road user. If it feels like you’re perennially stuck in traffic due to road construction, you’re not wrong, and you’re not alone, according to a new report by Transportation for America.
The nation’s largest 100 urban areas added 30,511 new lane-miles of roads between 1993 and 2017, according to the report, a 42 percent increase (and a trend that shows no signs of slowing down). For perspective, that’s higher than population growth, which was 32 percent in those metros over the same time period. That’s not all that grew: traffic congestion, as measured in annual hours of delay, actually rose during those 24 years, by a staggering 144 percent.
The report, called The Congestion Con, explores the recent history of road-building in the United States, and argues that if anyone hopes this kind of massive infrastructure investments will help solve city congestion and traffic woes, this is far from being the case.
The report breaks down exactly why expanding roadways has been such a bad deal for the country. There’s the expense, for one. Each lane-mile of road costs between $4.2 and $15.4 million to build and an $24,000 a year to maintain. States alone spent $500 billion to expand roads between 1993 and 2017.
Second, it’s guaranteeing more of the same, in terms of roads, repair costs, pollution, and congestion. It’s the theory of induced demand: Building more roads and adding more lanes gives the appearance of speeding up traffic. But by encouraging sprawl, it spreads out stores, houses, and jobs, providing more reasons to drive more place and expanding many people’s commutes. It also adds more capacity, which is almost immediately filled up with more cars. Research by Kent Hymel of California State University of Northridge found that adding one percent more road capacity produces the exact same increase in the amount of vehicle miles traveled.