QuoteERIC JAFFE
Construction on the second phase of L.A.'s Expo light rail line is expected to be finished this month, with an opening scheduled for 2016. The project comes with high hopes of reducing traffic congestion in America's most notorious car town. That goal was outlined in the environmental analysis for the original leg of the line, from Downtown L.A. to Culver City, and was reiterated by Mayor Eric Garcetti this summer in discussing the extension to Santa Monica:
"The region's newest rail line will add another transportation route while relieving traffic and reducing greenhouse gas emissions in the process."
It's common, if not almost required, for major transit projects in the U.S. to carry promises of traffic relief. In a practical sense they'd be foolish not to. Most Americans still drive from here to there, and winning the favor of the majority is the job of the politician. So we see all sorts of public transportation efforts tout the benefits they'll have on congestion: from light rail to metro rail to bus-rapid transit to bike-share.
There's just the little problem of the evidence. With few exceptions, studies tend to find limited signs that transit has much of an impact on nearby road congestion. Some places see slight congestion gains or mileage declines in the short term, and well-designed service should lay the foundation for reduced car-reliance in the long run, but the direct transit-traffic link is tenuous at best.
Full article: http://www.citylab.com/cityfixer/2015/10/public-transit-does-not-have-to-reduce-traffic-to-succeed/409447/
Mass transit never reduces traffic congestion for those willing to drive. Trying to make that connection set mass transit in the US back 20 years. Mass transit is like aspirin, it only works for you if you use it. Any empty space on the highway resulting from a mass transit rider will just be taken up by the next car in line.