Of course, MUPs are safer. Yes, they might be busy at times - you got slow down. Or you have to cross intersections with auto traffic - ok, but that's probably also true if you ride on the street??

After all this is a Commuting forum - meaning we are talking about getting to and from work on our bikes. We are not talking about road/racing/mountain biking whatnot.

Riding on the streets is inherently more dangerous. Some good advice here about taking the road, VC and wearing reflective clothes, lights and helmet etc, but all that is not a guarantee. If you still get hit by a car at 40 mph you're not gonna like it and you're not going to be ok (even the Lance-types here who claim a 25mph average speed- first you get hit at 15mph and than you smash into the road with 25mph). Yes, you can still fall off your bike on a MUP and get hurt... but let's be serious.