U.S. Route 1 Alternate was established in 1953 when US 1 was rerouted to bypass west of Wake Forest and Youngsville. Predominantly a two-lane highway, with either a median or tree divide in Wake Forest, it follows the old alignment; via Main Street, Youngsville Boulevard, College Street and Park Avenue.
Franklinton
U.S. Route 1 Alternate was established in 1953 when US 1 was rerouted to bypass west Franklinton. A two-lane urban highway, it follows the old alignment through the downtown area, via Main Street.
U.S. Route 1A in Connecticut is a short loop route within the town of Stonington that passes through Stonington borough. US 1 originally went along this route until 1941. US 1A is the only surviving alternate U.S. highway in Connecticut. The route is long and takes the following route: From US 1 to North Water Street, to Trumbull Avenue, to Alpha Avenue, then to Elm St, and back to US 1. ;Major intersections
U.S. Route 1A is a numbered U.S. Highway running in the U.S. state of Rhode Island. It serves as a bypass of the downtown areas of Providence and Pawtucket, which US 1 goes through. US 1A is a lengthier route than the section of U.S. Route 1 that it bypasses. US 1A should not be confused with Rhode Island Route 1A. In Rhode Island, US 1A exists in two segments in Providence County connected by a mostly-unsigned concurrency with I-195, while Route 1A serves as a scenic alternate route of US 1 in Washington County. Not helping matters is the presence of Route 1A shields on US 1A. ;Route description US 1A runs for through Warwick along Post Road and Warwick Avenue. Then in Cranston: it runs for another continuing along Warwick Avenue to Norwood Avenue and Narragansett Boulevard before crossing into Providence. There, the highway continues to follow Narragansett Boulevard and turns along Allens Avenue, Eddy Street, Point Street. US 1A is not signed at all in Providence, but in all likelihood, from Point Street, US 1A uses Water Street to enter I-95 EB at Exit 1D. Similarly, US 1A SB probably exits I-195 WB at Exit 1D onto Water Street, and turns left onto Point Street. The highway continues on the East Providence Expressway into East Providence. US 1A uses another one-way pairing with the eastbound traffic using the expressway, and Warren and Pawtucket Avenues. The opposite direction is routed along Pawtucket and Newport Avenues. The last city through which US 1A runs is Pawtucket where it runs for to the Massachusettsstate line in Attleboro, traveling concurrently with Route 1A on Newport Avenue to U.S. Route 1. ;History US 1A is not a former alignment of US 1. In Warwick, US 1A formerly ran further north along Post Road east of Route 117 instead of turning north to overlap with the state road. It stayed with Post Road through Pawtuxet Village, then traveled north into Cranston on Broad Street to rejoin the current alignment at Norwood Avenue. The southernmost section of the route, which exists on Post Road, was part of the Boston Post Road, a former mail route. ;Major intersections Exit numbers concurrent with I-195 are scheduled to be converted to mileage-based exit numbering in 2020.
This US 1A segment in York travels along the coast and serves the areas of York Harbor and Cape Neddick. The length of this segment is 7.0 miles.
Portland
In Portland, Maine's largest city, the original routing of what was US 1A has largely been eliminated but a short section still exists mainly along Portland's waterfront. It now begins at exit 7 on the I-295 freeway. It travels east along the Franklin Street Arterial until its intersection with Commercial Street and the Maine State Pier. At this point it makes a 90-degree turn onto Commercial Street, which it will follow through the entire waterfront area passing such landmarks as Becky's Diner and the US Customs Service Portland office. It then passes under the four lane ME 77/Casco Bay Bridge roadway, and then continues along Commercial Street until its intersection with Valley Street and the Veteran's Memorial Bridge Road. US 1A follows neither routing but instead turns west and north following the Fore River Parkway where it loops back to meet I-295 again at the exit 5 interchange, which also serves Congress Street.
Rockland
US Route 1A in Rockland bypasses the downtown area and begins at the intersection of Camden and Maverick Streets. Traveling westbound along Maverick Street, it passes Rockland Plaza, and is concurrent with Maine 17 along this section. It then takes a 90 degree turn at a flashing yellow blinker light to turn left onto Birch Street where it meets North Main Street at a traffic light. US 1A then continues along Broadway, passing Oceanside High School as it continues south through the residential heart of Rockland, and encounters additional traffic lights at Rankin and Limerock Streets, until its end at a traffic light at Park Street where it rejoins US 1.
US 1A in Bangor is a loop route off U.S. Route 1 in Maine, serving the Bangor metropolitan area. The route is 54.0 miles long and runs from Stockton Springs to Ellsworth. Route 1A enters Bangor from the southwest by following the west bank of the Penobscot River through the towns of Winterport and Hampden. Route 1A crosses the Joshua Chamberlain Bridge from downtown Bangor into the city ofBrewer, and continues southeast through Holden and Dedham to Ellsworth.
Milbridge
In Milbridge, US 1A provides a more direct route for through travelers, as it branches off from US 1 just north of the main business section of the small town of Milbridge, and is known as Bridge St. It then crosses the Narraguagus River and continues in a northeasterly direction whereas US 1 takes a route that is north/northwest to meet Cherryfield before turning back east while 1A takes the more direct route closer to the coast to rejoin its parent just east of Harrington. The length of this segment is 7.8 miles.
This section of US 1A runs 8.1 miles between Jonesboro and Machias via the village of Whitneyville.
Aroostook County
In Aroostook County, US 1A runs, from Mars Hill to Van Buren. Route 1A runs parallel to the Canadian border, as U.S. Route 1 goes through the cities of Presque Isle and Caribou. Major towns along US 1A include Fort Fairfield and Limestone. The section north of Fort Fairfield to Van Buren was once State Route 165, but is no longer a numbered highway in Maine.
Routed along King Street, Willet Avenue, Putnam Avenue, and Hillside Avenue.
Darien, Connecticut
Current US 1 alignment. In the early 1950s, a 4-lane divided highway was constructed to relieve congestion in the area. US 1 was assigned to this new highway section with the old road becoming US 1A. The highway section was later incorporated into the Connecticut Turnpike and eventually became I-95. US 1 was re-designated on the old alignment.
Norwalk, Connecticut
Routed along Belden Avenue, Cross Street, and North Avenue. US 1 was originally assigned to West Street, Wall Street, and East Avenue. Since the opening of the US 7 expressway, US 1 was moved to its current alignment along part of this US 1A along Riverside Avenue, Cross Street, and North Avenue. The original US 1 alignment is now town-maintained.
Current US 1 alignment along Kings Highway Cutoff, North Avenue, Boston Avenue, and Barnum Avenue. This US 1A existed until 1963. US 1 originally went along modern Route 130 on Fairfield Avenue, State Street, Stratford Avenue, and Ferry Boulevard connecting the towns of Fairfield and Stratford via downtown Bridgeport.
Milford, Connecticut
US 1 originally went along Broad Street, River Street, and Cherry Street. Current US 1 was designated as US 1A. In 1940, the two alignments were swapped. US 1A remained on Broad Street/River Street/Cherry Street until about 1942. Broad Street is now part of Route 162 while River and Cherry Streets are now town-maintained roads.
East Haven, Connecticut
Routed along Main Street. This was the original alignment of US 1 until the opening of the Saltonstall Parkway in 1941, which was designated as US 1. This US 1A existed until the early 1950s. The eastern end of Main Street is now part of Route 100.
Branford, Connecticut
US 1 originally went along Main Street and East Main Street. From 1937 to 1940, current US 1 on North Main Street was designated as US 1A. The routes were swapped around 1940 and US 1A remained on this alignment until 1963. Main Street is now part of Route 146 while East Main Street is a town-maintained road.
US 1 originally went to the town center using Old Boston Post Road then Main Street. US 1A was designated on the current US 1 alignment on Boston Post Road. The two routes were swapped around 1940. US 1A on Old Boston Post Road remained until the early 1970s.
Waterford, Connecticut
In late 1948, an expressway section between the Raymond E. Baldwin Bridge in Old Lyme and the Gold Star Bridge in New London was opened. US 1 was assigned on this new expressway alignment. The original route of US 1 became US 1A. The US 1 expressway later became part of the Connecticut Turnpike and I-95. The US 1 designation was removed from the expressway in 1975 and reverted to its old surface alignment.
Groton, Connecticut
Long Hill Road from the I-95 Exit 85 offramp to Poquonnock Road. This was a newly constructed road in 1938 which later became US 1 by 1941. The original US 1 alignment used Thames Street and Poquonnock Road going through the old Borough of Groton.
