 At the northeastern terminus, the Baltimore Beltway was planned to extend southeast along the Back River Neck peninsula and turn south to cross the river near the Essex Skypark Airport, heading towards an outer crossing of the Patapsco River. Part of this alignment was completed south of US 40 in 1972 with a further extension to MD 150 opening as the Southeast Freeway (designated MD 702) by 1975. However, the Baltimore Beltway was diverted to two freeways not planned to be part of it. The first was the Windlass Freeway (MD 149), a route planned to run from I-95 at Moravia Road northeast to Chase, paralleling US 40 to the south. The other freeway that was incorporated into the Baltimore Beltway was the Patapsco Freeway, a short connector from the Windlass Freeway southeast to the originally-planned Baltimore Beltway. Only the segment of the Windlass Freeway between MD 702 the planned intersection with the Patapsco Freeway south to MD 151 (North Point Boulevard) were constructed, opening to traffic in 1973.
