I don't know how many cities have something like this, but Minneapolis has a program where if you use a bike as your main commute they will actually coupons to take the bus or a cab for days when there is bad weather or you get a flat tire or something.

http://www.ci.minneapolis.mn.us/bicy...d-ridehome.asp
This is a link to our program. I just thought this is a pretty good backup plan and a valuable program for bike commuters!