I was bored last night, and decided to look up the St Louis County vehicle codes, and came across this (
rather technical) description on how roads are to be constructed, the widths involved, and other details. The standard width of a lane is supposed to be 12 feet on a highway, and in a residential street, the lane should be 10 feet. On some residential streets, there are simply lanes to park, and a lane down the middle for traffic to pass by. Canfield Drive wasn't one of those streets, and I still don't understand why they were walking in the street.