How wide do auto lanes need to be?

There's really no way of avoiding this essential fact: the addition of a cycle lane/track to an existing roadway inevitably means less space for automobiles. The key question is how much less space and, following from this, whether it can be taken from existing travel and/or parking lanes. The answer to this question depends on what we think is the minimum width of an auto travel lane. This, I believe, to be one of the thorniest of issues related to implementation of Mission's Transportation Master Plan (TMP). This is partly because it runs counter to the prevailing ideology: the wider the lanes, the better. Mission's TMP suggests that these days are over, at least in theory. The question now for many cities in North America is not how wide to build travel lanes, but how narrow.

John Belec