An article on CityLab, a site that brings scientific thinking to the questions of urban life, investigates the current state of traffic engineering for lane width, and the author lays down a compelling argument about making things narrower. Two-feet might not sound like a lot, but when multiplied over the whole roadway, you end up with quite a bit of extra real estate to play with.
The piece explains some of the reasons that 12-foot lanes are the standard in the first place and then breaks each of those arguments down to show that they might be a fallacy. If nothing else, the story makes you think more about traffic engineering than you probably have in years. Read the whole story for yourself, here.