My post on the strategic value of chokepoints, using the example of chokepoint-rich Seattle, led to an interesting comment thread at the Seattle Transit Blog. As often happens, discussion quickly turned to my references to rail and Bus Rapid Transit, as readers argued over whether my real agenda was to advance one of those modes.
As regular readers will know, it’s rarely that simple. But chokepoints do point to an advantage for Bus Rapid Transit if you’re trying to do things cheaply. That advantage is that a chokepoint that affects private vehicle traffic is effectively a kind of traffic meter. In our* work for Seattle Dept. of Transportation in the mid 00s, for example, we noticed that congestion was actually worse at the chokepoints around the edges of downtown than right in the center of downtown. The chokepoints were restricting the rate of flow of vehicles so that they couldn’t congest the core, exactly the way a system of freeway ramp meters can limit congestion on a freeway. Continue Reading →