+1 on dasgeh’s comment – it entirely depends on where you’re headed. I’ve ridden the CCT for many years now and developed different routes based on where I need to get to.
Generally if I’m heading to the West End/Foggy Bottom, I’ll ride (on the road) on Water/K St. until 29th, then take a left and ride up to M, then a right turn onto Penn Ave and go from there.
Towards the White House – or, more importantly, Swings for Friday Coffee Club, I’ll ride on Water/K up to the nasty little intersection with 27th and the Whitehurst (AMIRITE?), then on up to Washington Circle and onwards to where I need to go on Penn.
If its Hains Point or VA, or something in that direction, I’ll take Water/K and then instead of the left onto 29th, I’ll head the opposite way along RCP. I take the trail all the way to the John Ericsson Memorial Ciricle, then hop on Ohio Dr. and ride the road thereafter. I just dont have the patience anymore to deal with the RCP under the Kennedy Center and by the monuments.
Generally on Water St. you wont encounter too much traffic – be wary of some cars speeding up and down the stretch closest to the trail. A *lot* of out-of-town drivers think they’ve discovered some secret way around G-town traffic, only to see No Outlet signs at the end of Water St. (That, and when looking at their GPS’s, they think they’re on the Whitehurst when they’re really on Water St. )
Occasionally cops set up stop-sign blitzes to ticket cyclists – maybe 3 or 4 times a year.