Boston case shows declining car volume on major street

When it comes to planning street infrastructure, there is a rule of thumb traffic engineers use when designing roads. That rule is that vehicle volumes will always go up, usually at 0.5% a year. That’s what results in roads almost always being overbuilt, as a street designed today is built to comfortably hold projected traffic 50 years from now. As the projects always show increasing vehicle volumes, we get extra lanes and such.

But what if that prediction and the rule of thumb is wrong?

Can a city gain residents and grow economically if traffic values stay constant….or even decline? As one study in Boston shows, the answer is absolutely yes.

Boston University recently released their campus plan and it includes a discussion on Commonwealth Avenue. That road is the heart of campus, but is also one of the few east-west roads available in this part of the city. Besides students, teachers, staff and others associated with the university, Comm Ave is used to access many businesses, reach the Allston and Brighton neighborhoods of Boston, and is monumentally important to folks arriving for games at Fenway Park and also events at Agganis Arena.