On my commute to work, if there a cyclist in front of me, is it rude to catch up and draft? To effectively draft I would usually need to be within a foot of their back wheel.
There are two situations:
Trainers There is one part of the commute that is often used by individuals and groups of riders who seem to be training rather than commuting. Generally I would draft these guys if I can sprint to catch them. As they are going quicker than I can sustain, I never take a turn at the front.
Commuters I think any fellow commuter is probably ok to draft and if they slow down enough I'll take a turn at the front.