This is the only utility corridor on this list to stretch into Alexandria, and it then heads south across Fairfax where there are already short trail segments on the corridor.
On the east end, the corridor starts just inside the beltway at the water treatment plant and then moves into the same corridor as the Beltway. This is not impossible for a trail to navigate, but it would mean placing a trail in between a freeway and its ramps, or other facilities, on top of what is now a drainage ditch. And at least one bridge would be needed over Hooff Run. It's probably not worth it, even if it does create a connection to the Eisenhower Avenue Metro.
Getting across the Beltway there would be very difficult too. Better to just use the trail on Eisenhower and the ramp to Telegraph Road. But it's nice to have options.
From there, the corridor - now in Fairfax County - becomes a lot easier to use all the way to S. Van Dorn Street. In fact for most of the way between S.Van Dorn and Rose Hill there's already a trail. Between Van Dorn and Hayfield the corridor runs along Manchester Boulevard and over some parking lots, making it harder to adapt, but at Hayfield another trail picks up (and diverts along a spur to Kingstown Village Parkway) and the corridor becomes easy to adapt all the way to I-95 and the railroad line east of it. The spur is also adaptable up to that point.
Interestingly, a bridge for either of those over the railroad would create a connection to the Fairfax County Parkway Trail.
There's no way to cross I-95 by bike between Rolling Road and the Franconia-Springfield Parkway (and maybe that should be fixed) but once on the west side it again becomes a good corridor all the way to the Occoquan. One small section has a trail on it and the corridor is criss-crossed by trails in the South Run Stream Valley Park. It also connects with the Cross County Trail, some sidepaths along Pohlick, Ox and Silverbrook Roads and another corridor that goes to Middleburg, VA. On the downside, crossing some of the roads would be unpleasant without grade separation.
On the other side of the Occoquan, in Prince William County, the corridor gets more difficult with lots of water crossings, another crossing of I-95 and some wetland issues. But certainly parts could be adapted. There are two parallel corridors in that part of the County that lead to the Possom Point power plant - the other one goes to Idylwood - and it might make sense to focus on the other one first, or to find a way to use parts of each. Along the way it intersects another corridor, and then there are a few other lines that come out of Possom Point.
Comments