Whenever Seattle’s various master plans (Transit, Bicycle, Pedestrian, Freight) are the subject, it’s fashionable to decry segmentation of transportation plans into “silos,” because who could be against a holistic, unified plan?
Well, a plan that tries to solve every problem won’t do very well at any of them. In any case, the SDOT staff I talked to about the Freight Master Plan were very eager to tell me how much they were cross-checking all of the other modal needs at every step. But in the comments in that piece Al Dimond offers a very reasonable defense of silos:
It is, of course, important to think about how all modes work in a corridor when that corridor is being designed.
It is also important to think about how all the city’s transportation corridors combine into a network for each particular mode of travel. It can reveal gaps that corridor-based thinking misses. One of the most glaring examples in Seattle is the gap in our cycling network south of downtown. In every specific corridor a combination of weak cycling advocacy and strong trucking opposition has doomed bike facilities. But when we look at the cycling network as a whole it’s clear that a bike route is necessary in the general area, even if none of the individual corridors cry out for it.
Of course the example that comes to mind first for me is a cycling example, since I get involved in that more than other stuff, but it wouldn’t be hard to come up with driving, freight, and transit examples where whole-network mode-specific thinking is needed to identify weaknesses and inform and prioritize improvement projects.