This is a singular place on the trail, in that there is a nearby large parking lot on MD-40 that accesses this point. From here you can go in this direction on the Appalachian Trail, pass under the MD-40 bridge, shown here, make a right turn (to the north), and hike up the hill to Pine Knob and Annapolis Rocks. For this short distance before the MD-40 bridge, the trail is parallel to I-70 (seen to the left in this photo).

But suppose you want to hike south on the trail. In this picture, you are looking south across this fabulous foot bridge, which crosses I-70. Instead of hiking parallel to the interstate and then under MD-40, you can cross the interstate on this foot bridge and hike south to the Washington Monument, as you can see in this sign. Note the vine growing over everything here; aptly called mile-a-minute vine (Persicaria perfoliata), and is projected to cover the world, where kudzu failed (*heh*). To be fair, this vine actually grows mainly in sunny areas in the margins of woods, just like kudzu.

This is the view from the foot bridge looking north. If you walk up the steps at the north end of the bridge, you can follow a path to the parking lot. If you turn left, instead, then you start hiking the Appalachian Trail north toward Pine Knob and Annapolis Rocks.