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.