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.
U.S. Route 89 in Utah
US-89 leaves Salt Lake City at exit 312 of I-15, where it acts as I-15's frontage roads. Just south of I-15's junction with I-215, US-89 splits to the northeast, passing through Bountiful and Woods Cross. A northerly curve onto 500 West removes the highway from Bountiful's Main Street, and it merges with I-15 at exit 317 to bypass Centerville and Farmington, where the old road (former US-91, but never US-89) is SR-106, through the narrow strip of land that separates Farmington Bay from the Wasatch Mountains. US-89 leaves I-15 at exit 324, where the Legacy Parkway also ends, and proceeds north on a freeway. This portion of US-89 is the only one to include exit numbers based on its own mileage, as opposed to the overlapping I-15 or I-70. The freeway ends after US-89 crosses SR-273, the former surface alignment of US-91 in both directions, and heads north as a four-lane road along the Wasatch foothills, to the east of Layton and Hill Air Force Base. After crossing I-84 in Uintah, US-89 enters Ogden, which it traverses via Washington Boulevard, rejoining old US-91 (now SR-26) south of downtown. Beyond Ogden, US-89 continues in a general northerly direction along the thin strip between Willard Bay and the Wasatch Mountains to Brigham City, where it finally turns east away from the I-15 corridor.