If you want, you can detour around it so you don't have to squeeze through the fence. If you're headed west, make a right when you get to Erskine St. (by the Target/Home Depot mall), then make your first left (in front of the mall.) You can loop around and come up to Flatlands, make a left, go to Pennsylvania Ave. and make another left, and that'll take you back to the bike path right on the other side of the construction. The roads are mostly in pretty good shape, although watch out for some sketchy driving!