U.S. Route 1

US 1 travels along the east coast of Florida, beginning at 490 Whitehead Street in Key West[5] and passing through Miami, Hollywood, Fort Lauderdale, Boca Raton, West Palm Beach, Jupiter, Fort Pierce, Melbourne, Cocoa, Titusville, Daytona Beach, Palm Coast, St. Augustine, and Jacksonville. The southernmost piece through the chain islands of the Florida Keys, about 100 miles (160 km) long, is the two-lane Overseas Highway, originally built in the late 1930s after railroad tycoon Henry Flagler's Florida East Coast Railway's Overseas Railroad, which was built between 1905 and 1912 on stone pillars, was ruined by the 1935 Labor Day hurricane. The rest of US 1 in Florida is generally a four-lane divided highway, despite the existence of the newer I-95 not far away. Famous vacation scenic route State Road A1A is a continuous oceanfront alternate to US 1 that runs along the beaches of the Atlantic Ocean, cut only by assorted unbridged inlets and the Kennedy Space Center at Cape Canaveral. North of Jacksonville, US 1 turns northwest toward Augusta, Georgia; US 17 becomes the coastal route into Virginia, where US 13 takes over.[6] In Florida until the 1990s, US 1 used high-contrast markers (white text on a red background).[7]

The part of US 1 in Georgia, as it shifts from the coastal alignment in Florida to the Atlantic Seaboard Fall Line alignment in South Carolina, is generally very rural, passing through marshes and former plantations between the towns and cities of Folkston, Waycross, Alma, Baxley, Lyons, Swainsboro, and Augusta. The Georgia Department of Transportation has an ongoing plan to widen all of US 1 to four lanes with bypasses, which is more than 50 percent complete.

In South Carolina, US 1 generally serves mostly rural areas as it falls west of I-95 while the coastal areas are served by routes east of it. Starting in South Carolina, US 1 is paralleled by I-20 along the Atlantic Seaboard Fall Line through Aiken, Lexington, and Columbia to Camden and Lugoff. US 1 functions as a local two-lane road with occasional boulevard stretches. After Camden, US 1 continues northeast away from any Interstate toward Bethune, Patrick, McBee, and Cheraw with no bypasses or four-lane sections except around Cheraw through the US 52 and South Carolina Highway 9 (SC 9) concurrencies. After SC 9, it continues northward into North Carolina as a two -lane highway. The South Carolina Department of Transportation (SCDOT) has no plans to widen or bypass any US 1 alignments northeast of Camden to the North Carolina line.

Between the South Carolina line and the US 74 bypass, US 1 is a two-lane road but sees a considerable amount of truck and tourist traffic of people cutting through from the US 74/US 220 and I-73/I-74 corridor attempting to reach points south and east. US 1 goes through downtown Rockingham, with a bypass in the future plans. North of the North Carolina Highway 177 (NC 177) junction, it becomes four lanes or greater, becoming a superstreet with limited access and then becoming a limited access freeway. US 1 becomes a major artery for the state as it moves north of Rockingham. After Richmond County, it goes into Moore County with two expressway bypasses in Southern Pines, Vass, and Cameron. US 1 continues with the Jefferson Davis Highway label through Lee County and Sanford, and on to Cary and Raleigh. US 1 runs concurrently with US 64 through most of Cary, where the freeway recently underwent a major renovation and improvements that added lanes in both directions.[8] North of Raleigh, US 1 (known as Capital Boulevard in northern Wake County) crosses I-540 and then again becomes a four-lane divided arterial to I-85 near Henderson. The North Carolina Department of Transportation (NCDOT) has begun a corridor study for this section of US 1.[9] Moreover, NCDOT is planning to finish four-laning US 1 in Richmond County past NC 177 with a Rockingham bypass to the east. There are no plans from SCDOT to widen US 1 from the state line. From Henderson into Virginia, US 1 runs parallel with I-85 as a two-lane local road until the state line, where Virginia hosts a continuous third center lane for alternate passing toward US 58 before South Hill.

In the Mid-Atlantic, US 1 generally serves some of the most populated areas of the east coast. Through Virginia, US 1 is paralleled by Interstates: the remainder of I-85 to Petersburg, I-95 through Richmond and Fredericksburg to Alexandria, and I-395 into Arlington. In much of Virginia, US 1 was called the Jefferson Davis Highway by state law, although there are exceptions. South of Petersburg, it is known as Boydton Plank Road. Through some of Fairfax County and Alexandria, it is called the Richmond Highway.[10] In February 2021, Virginia renamed all remaining portions of the Jefferson Davis Highway in the state to Emancipation Highway beginning on January 1, 2022.[11][12]

US 1 crosses the Potomac River with I-395 on the 14th Street bridges and splits to follow mainly 14th Street and Rhode Island Avenue through the District of Columbia. US 1 is at the minimum of three lanes (with alternate passing) from the North Carolina state line to Petersburg with occasional four-lane divided sections. North of Petersburg is a four-lane undivided roadway at the minimum to the DC line. The route of US 1 from Petersburg to the state line is parallel with the Atlantic Seaboard Fall Line. From Petersburg onward, it is parallel with I-95. After exiting DC into Maryland, US 1 follows the Baltimore–Washington Boulevard, the first of several modern highways built along the Washington–Baltimore combined statistical area corridor; I-95 is the newest, after the Baltimore–Washington Parkway. US 1 runs through the University of Maryland, College Park, campus in College Park, Maryland. The route bypasses Downtown Baltimore on North Avenue and exits the city to the northeast on Belair Road, gradually leaving the I-95 corridor, which passes through Wilmington, Delaware, for a straighter path toward Philadelphia. Around and beyond Bel Air, US 1 is a two-lane road, crossing the Susquehanna River over the top of the Conowingo Dam before entering Pennsylvania. (Routed further north, US 1 bypasses the state of Delaware, unlike I-95.)[6]

The two-lane US 1 becomes a four-lane expressway, officially known as the John H. Ware III Memorial Highway, after the Pennsylvania representative, just after crossing into Pennsylvania. This bypass extends around Oxford and Kennett Square, merging into the four-lane divided Baltimore Pike just beyond the latter. At Media, US 1 again becomes a freeway—the Media Bypass—ending just beyond I-476. After several name changes, the road becomes City Avenue, the western city limits of Philadelphia, at the end of which a short overlap with the Schuylkill Expressway (I-76) leads to the Roosevelt Expressway and then the 12-lane Roosevelt Boulevard partly overlapping US 13. US 1 again becomes a freeway after leaving the city, bypassing Penndel and Morrisville and crossing the Delaware River into New Jersey on the Trenton–Morrisville Toll Bridge.[6]

After crossing into New Jersey in Mercer County, US 1 continues on the Trenton Freeway through the state capital of Trenton and Lawrence Township as a four-lane freeway. As the freeway ends, the four-lane divided highway upgrades to six lanes north of I-295 passing through the Penns Neck section of West Windsor. Through Penns Neck is a series of traffic signals. The New Jersey Department of Transportation (NJDOT) is looking to revamp the highway through this area by replacing traffic signals with grade separations. The highway enters Middlesex County through Plainsboro Township and South Brunswick, where the highest point resides.[13] By Forrestal Village, the highway downgrades from six to four lanes until after Finnegans Lane in North Brunswick. Northward, it continues through New Brunswick as a short limited-access highway until the County Route 529 (CR 529)/Plainfield Avenue traffic signal in Edison. Through Edison and Woodbridge Township, US 1 has a mix of boulevard and limited-access segments and continues to do so after the US 9 juncture in the Avenel section of Woodbridge. The US 1/9 concurrency continues through the rest of the state. The six-lane divided highway remains through Rahway in Union County and Elizabeth, until it reaches Newark Liberty International Airport, where it becomes a dual carriageway freeway around downtown Newark in Essex County with a 2–2–2–2 configuration. The historic Pulaski Skyway takes US 1/9 into Jersey City, and the route exits the freeway at the Tonnele Circle to head north into Bergen County. US 1/9 turns onto US 46 as a limited-access highway, and the three routes run northeast to the George Washington Bridge Plaza, where they merge into I-95. US 46 ends in the middle of the bridge, which crosses the Hudson River into New York, and US 9 exits just beyond onto Broadway in Manhattan, but US 1 stays with I-95 onto the Cross Bronx Expressway, exiting in the Bronx onto Webster Avenue. Two turns take US 1 via Fordham Road to Boston Road, which it follows northeast out of the city, becoming Boston Post Road in Westchester County, never straying far from I-95. From the Bronx to the state line, it is a local road with two lanes in each direction, except in Rye where it has a single lane in each direction. As it enters Greenwich, Connecticut, it continues as a two-lane local road.

In New England, US 1 generally serves large cities in a side street capacity. In Connecticut, US 1 serves the shore of Long Island Sound parallel to I-95. Beyond New Haven, the highway travels east–west, and some signs in the state indicate this rather than the standard north–south. While I-95 in Rhode Island takes a diagonal path to Providence, US 1 continues east along the coast through Westerly to Wakefield-Peacedale, where it turns north and follows Narragansett Bay. Most of this part is a four-lane limited-access highway, providing access to Route 138 toward Newport. After Route 4 splits as a mostly-freeway connection to I-95, US 1 becomes a lower-speed surface road, passing through Warwick, Providence, and Pawtucket. The route parallels I-95 again through Providence and Pawtucket and into Massachusetts, traveling toward Boston as a four-lane road. When it reaches Dedham, US 1 turns east and becomes a freeway through metropolitan Boston, concurrent with I-95 and I-93 east to Braintree and north through Downtown Boston. The Tobin Bridge and Northeast Expressway take US 1 out of Boston, after which it again parallels I-95 as a high-speed surface road through Newburyport to the New Hampshire state line.[6]

The short portion of US 1 in New Hampshire follows the historic Lafayette Road, staying close to I-95, passing through Portsmouth before crossing the Piscataqua River on Memorial Bridge, which was demolished and replaced during 2012–2013, leaving a temporary gap in US 1. During construction, drivers had to detour to one of two other nearby bridges carrying US 1 Bypass or I-95. Within Maine, US 1 begins as a parallel route to I-95 near the Atlantic Ocean. At Portland, I-95 splits off to the north, and I-295 heads northeast paralleling US 1 to Brunswick. There US 1 turns east as a mostly two-lane road along the coast to Calais; much of this portion is advertised as the "Coastal Route" on signs. North from Calais, US 1 follows the Canadian border, crossing I-95 in Houlton and eventually turning west and southwest to its "north" end at the Clair–Fort Kent Bridge in Fort Kent. The short Route 161 extends north on the New Brunswick (Canada) side of the bridge to Route 120, a secondary east–west route from Edmundston, New Brunswick, west to Quebec Route 289 toward Saint-Alexandre-de-Kamouraska, Quebec.[6]