U.S. Route 1 Alternate (US 1 Alt.) is an alternate route of US 1 in the U.S. state of Maryland. The highway runs between intersections with US 1 in Arbutus and in Baltimore. US 1 Alt. serves the southwestern Baltimore County community of Halethorpe and connects US 1 with full-access interchanges with Interstate 95 (I-95) and I-695. The Washington Boulevard portion of the alternate route was the original road southwest from Baltimore in the 18th century and was part of the turnpike southwest to Washington, D.C. for much of the 19th century. The highway was paved in the early 1910s, expanded in the late 1910s and late 1920s, and became part of US 1 in 1926. The Caton Avenue portion of the alternate route was improved and expanded in the 1930s to serve as a rerouting of US 1 in southwest Baltimore. US 1 Alt. was created in 1949 when US 1 was moved to its present course through Arbutus and southwest Baltimore. The alternate route's interchanges with I-695 and I-95 were constructed in the late 1950s and mid-1970s, respectively.
Route description
US 1 Alt. begins at a partial interchange with US 1, which heads north as Southwestern Boulevard through Arbutus and south as Washington Boulevard toward Elkridge. There is no access from southbound US 1 Alt. to northbound US 1 or from southbound US 1 to northbound US 1 Alt. US 1 Alt. heads northeast as Washington Boulevard, a four-lane undivided highway that immediately crosses over Amtrak's Northeast Corridor railroad line, which carries MARC Train's Penn Line, and Herbert Run. The highway passes through Halethorpe, where the route temporarily expands to a divided highway through its three-ramp partial cloverleaf interchange with I-695 (Baltimore Beltway). There is no ramp from eastbound I-695 to US 1 Alt.; that movement is made via a ramp from eastbound I-695 to Sulphur Spring Road, which intersects US 1 Alt. at the I-695 junction, at the I-95–I-695 interchange to the west.
US 1 Alt. continues northeast to an intersection with Caton Avenue and Hammonds Ferry Road just south of the Baltimore city limits. The alternate route leaves Washington Boulevard to turn north onto four-lane divided Caton Avenue and enters the independent city. US 1 Alt. then meets the western end of Patapsco Avenue at a directional intersection from which the latter avenue heads southeast. There is no direct access from Patapsco Avenue to the southbound alternate route or from the southbound alternate route to eastbound Patapsco Avenue; those movements are made via Washington Boulevard. US 1 Alt. heads north as a six-lane divided highway through a seven-ramp partial cloverleaf interchange with I-95. The highway reduces to a four-lane undivided highway and passes by Seton Keough High School, the former Cardinal Gibbons School, and St. Agnes Hospital before reaching its northern terminus at US 1 (Wilkens Avenue). Caton Avenue continues north through western Baltimore toward MD 144 and US 40.
All of US 1 Alt. is a part of the National Highway System as a principal arterial.
History
Washington Boulevard was first laid out as the highway southwest from Baltimore in 1741 and was improved by the Baltimore and Washington Turnpike Company starting in 1812. After the state condemned the turnpike in 1865, maintenance of the highway became the responsibility of the counties. In 1906, the state took over maintenance as the road as part of its construction of State Road No. 1. The highway from west of the Pennsylvania Railroad (now Amtrak's Northeast Corridor) to the city limits of Baltimore at Gwynns Falls was reconstructed as a concrete road by 1915. The work included a bridge across the Pennsylvania Railroad at Winans. Washington Boulevard was widened to with a pair of concrete shoulders and resurfaced with sheet asphalt in 1918, part of a project to expand the entire highway from Washington, D.C. to Baltimore to . The highway, which was marked as US 1 in 1926, was widened to with the addition of a pair of concrete shoulders, and resurfaced with sheet asphalt in the late 1920s.