Originally Posted by
chipcom
+1 If you need to go faster than 15mph, get off the MUP and use the road.
MUPs in the DC area probably aren't like what you and Maddyfish are used to in the Midwest - and I can tell you the roads aren't either. My local MUP is a 9-foot wide paved rail-trail, and it can easily support over 15 mph (in fact, I do so every day). Mine also gets overpasses that lets me skip 5 of the worst intersections on my commute, making it a lot faster and more fun.
Riding on road around here, on the other hand, ain't so fun. Avoiding our utterly dysfunctional roads is at least half the reason I started riding to work, and I suspect I'm not alone. EDIT: Yes, they're worse here. I grew up in the midwest/south. Traffic is far, far better there.
For the most part, users on our local trails know how to coexist. The only time you have to really slow down is when the weather is outrageously nice - and around here, that ain't often - because it brings out a lot of people who don't get out much.
I'm riding the same trails as knucklesandwich, and have basically the same experience. There are a lot of commutes that would be pure hell without the trails.