That "incentive" already exists in the form of cheaper housing the further away you go.

I agree that commuting should be considered as part of "work", but I always took into account commute time when considering job opportunities. The pay obviously never had an explicit "commute" line, but my math was "this job + this commute for this pay". Figure if it's worth it or not.

I don't think people should be doing unpaid labor. What's the win-win?