Question: What highway system is being developed that lies west of Scherr, West Virginia?

Context paragraphs:
U.S. Route 340 in Maryland: U.S. Route 340 (US 340) is a part of the U.S. Highway System that runs from Greenville, Virginia to Frederick, Maryland.  In Maryland, the U.S. highway runs 17.01 mi from the Virginia state line at the Potomac River at Sandy Hook east to its northern terminus at US 15 and US 40 in Frederick.  US 340, which is known for most of its length as Jefferson National Pike, connects Frederick with the communities of Jefferson, Brunswick, and Knoxville in the southern part of the Middletown Valley of western Frederick County and Weverton in far southern Washington County.  The U.S. highway also links Frederick with Harpers Ferry and Charles Town in the Eastern Panhandle of West Virginia.  US 340 is a part of the National Highway System for its entire length in Maryland.

Scherr, West Virginia: Scherr is an unincorporated community in Grant County, West Virginia, United States.  The community's name is pronounced like "sheer."  Scherr lies to the west of the community of Greenland at the crossroads of West Virginia Route 42, West Virginia Route 93, and U.S. Route 48 (Corridor H).  Scherr is home to a rock quarry, asphalt plant, and a small country store.

U.S. Route 522 in West Virginia: U.S. Route 522 (US 522) is a part of the U.S. Highway System that runs from Powhatan, Virginia to Selinsgrove, Pennsylvania.  In West Virginia, the U.S. highway runs 19.0 mi from the Virginia state line near Ridge north to the Maryland state line at the Potomac River in Hancock just south of Hancock, Maryland.  US 522 passes through Ridge and Valley Province of the Appalachian Mountains in the Eastern Panhandle of West Virginia.  The portion of the U.S. highway in West Virginia serves to connect Winchester with Hancock via Berkeley Springs, the county seat of Morgan County.  US 522 is part of the National Highway System for its entire length in West Virginia.

U.S. Route 19 in Virginia: U.S. Route 19 (US 19) is a part of the U.S. Highway System that runs from Memphis, Florida to Erie, Pennsylvania.  In Virginia, the highway runs 88.89 mi between two pairs of twin cities: Bristol, Tennessee and Bristol, Virginia, at the Virginia–Tennessee state line, and Bluefield, Virginia and Bluefield, West Virginia, at the Virginia–West Virginia state line.  Between its endpoints, US 19 has lengthy concurrencies with US 11, US 58 Alternate, and US 460 during its course connecting Abingdon, Lebanon, and Tazewell within Washington, Russell, and Tazewell counties in Southwest Virginia.

U.S. Route 220 in Maryland: U.S. Route 220 (US 220) is a part of the U.S. Highway System that runs from Rockingham, North Carolina to Waverly, New York.  In Maryland, the federal highway runs 27.30 mi from the West Virginia state line at the Potomac River in McCoole north to the Pennsylvania state line in Dickens.  Known as McMullen Highway for much of its length in Maryland, US 220 is the primary north–south route in central Allegany County, connecting Cumberland with its southern suburbs and Keyser, West Virginia to the south and Bedford, Pennsylvania to the north.  The federal highway is part of the National Highway System between the West Virginia state line and Maryland Route 53 (MD 53) in Cresaptown and between Interstate 68 (I-68), with which it is concurrent through Cumberland, and the Pennsylvania state line.

U.S. Route 33 in Virginia: U.S. Route 33 (US 33) is a part of the U.S. Highway System that runs from Elkhart, Indiana to Richmond, Virginia.  In Virginia, the U.S. Highway runs 135.60 mi from the West Virginia state line near Rawley Springs east to its eastern terminus at SR 33 in Richmond.  US 33 is the primary east–west highway of Rockingham County, which lies in the Shenandoah Valley.  The highway connects the independent city of Harrisonburg (which also serves as the seat of Rockingham County), the town of Elkton, and an entrance to Shenandoah National Park.  East of the Blue Ridge Mountains, US 33 connects the Piedmont communities of Stanardsville, Gordonsville, and Louisa.  The U.S. Highway is a major suburban and urban route in the Richmond metropolitan area.  Within Richmond, US 33 runs concurrently with US 250.  SR 33 continues from US 33's eastern terminus as a state-numbered extension of the U.S. Highway that connects Richmond with Virginia's Middle Peninsula.

U.S. Route 50 in West Virginia: U.S. Route 50 (US 50) in West Virginia runs from the border with Ohio to Virginia, passing briefly through Garrett County, Maryland, and following the Northwestern Turnpike.  Prior to the U.S. Highway System it was West Virginia Route 1 and in the 1930s, the road was not finished in Maryland.  At that time, motorists had to open a gate at the state line and drive on a dirt path until again reaching the other state line.  Today the section of US 50 from Clarksburg to Parkersburg on the Ohio River is part of Corridor D of the Appalachian Development Highway System.

U.S. Route 48: Corridor H of the Appalachian Development Highway System, also known as U.S. Route 48 (US 48), is planned to run 148 mi from northern Virginia to central West Virginia.  It is being constructed from Interstate 79 (I-79) in Weston eastward across the crest of the Allegheny Mountains to I-81 in Strasburg, Virginia.

U.S. Route 250: U.S. Route 250 (US 250) is a route of the United States Numbered Highway System, and is a spur of U.S. Route 50.  It currently runs for 514 mi from Sandusky, Ohio to Richmond, Virginia.  It passes through the states of Virginia, West Virginia, and Ohio.  It goes through the cities of Richmond, Virginia, Charlottesville, Virginia, Staunton, Virginia, Waynesboro, Virginia and Wheeling, West Virginia.  West of Pruntytown, West Virginia, US 250 intersects and forms a short overlap with its parent US 50.  In West Virginia, the route is signed north–south.  In Ohio and Virginia, the route is signed east–west.

U.S. Route 522 in Virginia: U.S. Route 522 (US 522) is a part of the U.S. Highway System that runs from Powhatan, Virginia to Selinsgrove, Pennsylvania.  In Virginia, the U.S. highway runs 159.65 mi from its southern terminus at US 60 in Powhatan north to the West Virginia state line near Cross Junction.  In the Piedmont of central Virginia, US 522 is a minor highway connecting several county seats, including Powhatan, Goochland, and Culpeper.  North of Culpeper, the U.S. highway increases in importance, crossing the Blue Ridge Mountains, connecting Culpeper with Sperryville and Front Royal.  US 522 is mostly a four-lane divided highway north of Front Royal, where it passes through the Shenandoah Valley and the city of Winchester on its way to the Eastern Panhandle of West Virginia.  The U.S. highway is part of the National Highway System from SR 37 near Winchester north to the West Virginia state line.

Supporting paragraphs: Scherr, West Virginia U.S. Route 48
Answer: U.S. Route 48