U.S. Route 90
U.S. Route 90 (US 90) is an east–west United States highway. Despite the "0" in its route number, US 90 never was a full coast-to-coast route; it has always ended at Van Horn, Texas with the exception of a short-lived northward extension to US 62/US 180 near Pine Springs, Texas which lasted less than a year, and the signs on that segment were changed to Texas State Highway 54, traveling from Interstate 10 (I-10) at exit 140A and heading to its northern terminus at US 62/US 180.
Business routes of Interstate 90
Interstate 90 Business is a business loop of Interstate 90 in Rapid City. It runs from a diamond interchange at exit 52 (Peaceful Pines Road) in Black Hawk, then runs along the southeast side of I-90 on SD 231 (Sturgis Road), gradually moving away from that side of the interstate. Just before the intersection with Merritt Road, BL 90/SD 231 crosses the Meade-Pennington County Line. Within the Rapid City Limits, the concurrency with SD 231 ends at the intersection with West Chicago Street, and then it curves east onto West Main Street before it intersects SD 44 (Mountain View Road). In Downtown Rapid City, the route becomes a one-way pair which includes a brief two block overlap with US 16 until the intersections with East Street, where they turn north and intersect SD 44 a second time. Curving to the east at a railroad track, the road's name is changed to East North Street, then curves to the northeast at the intersection of North Campbell Street and finally terminates at a SPUI interchange with I-90 at exit 60. North of that interchange, East North Road becomes Tish Boulevard, a street within an unfinished industrial development leading to a city firehouse before becoming a dead end at a private one-lane dirt road.