In September 2017, Governor Larry Hogan announced a public-private partnership to tackle congestion on I-270 and I-495. The State Highway Administration’s website about the project includes a slide presentation on the many options under consideration.
Some of the options include widening I-270 by as many as four lanes. Not only would this devastate the neighborhoods where homes would be paved over to make room for additional lanes, it is well-documented that adding lanes to highways doesn’t actually do much to reduce traffic congestion.
Widening Highways Doesn’t Work
It may seem logical that adding more lanes would reduce traffic, but what actually happens is that more lanes attracts more drivers, and traffic builds up again. One recent review of several studies found that for every 1% of added highway capacity, congestion increased .68% within a year and as much as 1.1% within 5 years. (see here and here.)
In fact, California’s recently completed, $1.6 billion widening of the 405 actually lengthened average commute times!
A Highway “Boondoggle”
That widening highways doesn’t actually relieve congestion is one reason why the State’s $9 billion proposal for I-270 and I-495 landed on the U.S. Public Interest Research Group’s latest list of highway “boondoggles,” calling out expensive projects that would do little to solve problems and divert funds away from better solutions.
What’s a Better Way?
The Action Committee for Transit has outlined several options for expanding public transit instead of building more highways. And even the State’s own presentation shows many options other than widening the highway.