I had been wanting to explore some routes for getting to center city Philadelphia from Wilmington by bike and today I finally got the chance. Pennsylvania has marked bicycle touring routes (http://www.dot.state.pa.us/BIKE/WEB/tour_routes.htm) that cut through the state at various points and I happen to live near the start of both bike route L and E. Bike route E takes you from North Wilmington all the way through Philadelphia and a little bit beyond. For some reason the maps are not online like they are for the other routes. I planned on following the signs for around an hour and then heading home (an hour got me just past the airport from my starting point on Naaman's Road in DE). The route was a mix of two lane roads with NOL's and WOL's (usually doubling as a parking lane) and 4 lane roads with NOL's, WOL's, bike lanes, or shoulders with speed limits ranging anywhere from 25-50mph.
One reason that I am a DLP convert is the fact that so often in my area WOL's/shoulders/bike lanes just seem to end. The road narrows or the shoulder/bike lane becomes a right turn lane. Riding to the right at all times meant sometimes being caught offguard by these changes if on an unfamiliar road and ending up in a bad spot. Riding center by default gives me more time to assess the situation and I can decide whether or not to change position to allow faster traffic to pass or to make them wait/go around me.
Now, to my point. All of the bike lanes along the way (I rode the first 13 miles or so of the route with maybe 4 of those miles having bike lanes) were signed at the beginning and the END, usually accompanied by a "Share the Road" sign. I've never seen a shoulder or WOL lane signed saying that the width of the highway is going to be narrowing. These signs were quite helpful with deciding on my positioning as I could see them well ahead of me. I knew far in advance whether I should be looking to move left if I was right and if I should just stay left if I was left. At higher speeds it can sometimes be difficult to discern just how much the highway is narrowing especially if it's happening around a bend in the road.
So score one for well signed bike lanes. But deduct a half point for them being way dirtier than the WOL's
Side note: I think I saw the bravest old woman ever today, riding against traffic on a 50mph, 4 lane, NOL road. Now that takes guts.