U.S. Route 63 in Louisiana

From the south, US 63 begins at a diamond interchange with I-20 (exit 85) in Ruston, a city in Lincoln Parish. The interstate connects with the metropolitan areas of Shreveport to the west and Monroe to the east. US 63 heads north through the interchange overlapping the routes of both US 167 and LA 146. It is initially a divided four-lane highway with twin overpasses across I-20 via the one-way pair of North Trenton and North Vienna Streets. Almost immediately beyond the interstate, however, the travel lanes converge as North Trenton Street widens to an undivided four-lane highway with a center turning lane. US 63 proceeds in this capacity through the suburban area north of downtown Ruston and into the small rural town of Vienna. Here, LA 146 departs to the west, but US 63 will remain paired with US 167 throughout the remainder of its distance in Louisiana.[3][4][5]

Heading north through Vienna, the center lane gives way to a grassy median, and the highway begins to wind gently through the pine forests of northern Louisiana on a broad right-of-way. After passing through an area known as Unionville, US 63 enters Dubach and becomes locally known as McMullen Street. The right-of-way narrows and regains its center lane through the small town. Passing one block to the west of the old Main Street, US 63 briefly overlaps LA 151 as the latter zigzags between Annie Lee and Hico Streets. North of Dubach, the highway widens again and crosses into Union Parish about two miles (3.2 km) north of LA 545.[3][4][5]

In Union Parish, the highway enters another small town known as Bernice, where it divides onto the one-way pair of Cherry Street (northbound) and Plum Street (southbound). During this stretch, US 63 overlaps LA 2, which zigzags through town between 8th Street and 4th Street. LA 2 is a rural cross-state route connecting with Homer to the west and Farmerville to the east. North of 4th Street, US 63 begins to overlap LA 2 Alt., which utilizes the highway to connect to its parent route. About six blocks later, the one-way pair converges, and US 63 proceeds as an undivided four-lane highway with center lane until LA 2 Alt. turns off to the west toward Haynesville.[3][5][6]

Regaining its median and wide right-of-way, US 63 travels due north through the village of Lillie. Here, it intersects the northern terminus of LA 15 just west of Spearsville. North of Lillie, the highway curves to the northwest and travels for about seven miles (11 km) before reaching the larger village of Junction City. US 63 turns due north as the median is replaced by a center lane for the final time. Simultaneously, the highway begins to travel along the Union–Claiborne parish line while following South Main Street. The intersection of Main and Fifth Streets forms the northern terminus of LA 9, another connection to Homer, Claiborne's parish seat. Just two blocks later, at an intersection with Third Street, US 63 crosses the state line into the Arkansas portion of Junction City. Here, a roadside marker identifies the community as being located "at the junction of 2 states, 1 county, 2 parishes, and 3 congressional districts." US 63 proceeds north toward El Dorado, Arkansas still co-signed with US 167.[3][5][6]

US 63 is classified by the Louisiana Department of Transportation and Development (La DOTD) as an urban principal arterial in Ruston and as a rural principal arterial northward. Daily traffic volume in 2013 peaked at 18,900 vehicles in Ruston near the I-20 interchange and generally remained between 2,500 and 5,000 vehicles otherwise.[7] The posted speed limit is 65 mph (105 km/h) along the rural divided four-lane segments, reduced to 45 mph (70 km/h) along undivided four-lane portions and through most towns. It is reduced even further to 35 mph (55 km/h) within the city of Ruston and the town of Bernice.[3]

US 63 was designated in November 1926 as one of the original routes of the numbered U.S. Highway system.[8] It initially traveled from a junction with US 61 at Turrell, Arkansas (a point northwest of Memphis, Tennessee) to Des Moines, Iowa. In 1999, the American Association of State Highway and Transportation Officials (AASHTO) approved a relocation and extension of the route that moved its southern terminus to its present location in Ruston, Louisiana.[9] At this point, US 63 had terminated in Memphis proper by way of a concurrency with I-55. The change pulled the route back out of Tennessee and extended it southward from West Memphis, Arkansas for approximately 287 miles (462 km) over existing U.S. and state highways. The portion south of El Dorado, including its entire distance within Louisiana, overlapped part of US 167. In accordance with this decision, the Louisiana Department of Transportation and Development (La DOTD) added US 63 shields to the existing signage installations along US 167 between Ruston and the Arkansas state line. As of 2016, however, US 63 has not been added to the exit signage on I-20 at the new southern terminus.[3]

US 63 is Louisiana's most recent U.S. Highway designation, and it became the first within the state to terminate at an interstate highway. It is also the state's only U.S. Highway with the same number as a current state highway (LA 63).[1] In the past, state highways were renumbered when the introduction of a U.S. Highway caused such a duplication. However, LA 63 exists in a different region of Louisiana with confusion to motorists being highly unlikely.

Upon its extension into Louisiana in 1999, US 63 was a two-lane highway outside of the Ruston city limits.[10][11] However, plans had been underway for over a decade to widen the entire corridor to four lanes as part of an improvement project for the concurrent US 167. In 1989, the Louisiana Legislature approved the Transportation Infrastructure Model for Economic Development, or TIMED, program. Declared as "the single largest transportation infrastructure improvement program" in the state's history, it was initially funded from a 4¢ per gallon gasoline tax which allowed an estimated completion date around 2031.[12] After falling far behind schedule by the late 1990s, the legislature approved the first of several bond measures to fast-track the program, which included the widening of US 167 from Alexandria to the Arkansas state line (including the US 63 concurrency).[13] The work was carried out in stages throughout the 2000s and into the following decade.

In rural areas, the existing right-of-way was broadened to carry a divided four-lane highway with a wide median. The original road bed generally followed the present southbound lanes. In towns and other developed areas, the highway was widened to carry four travel lanes and a center lane with the major exception being the town of Bernice, where a one-way pair was used. Minor deviations from the original right-of-way occurred in Lincoln Parish between Vienna and Unionville, where a series of curves were straightened somewhat. Several portions of the old road survive as dead-end local roads in this area. The widening of US 167 was one of the last TIMED projects to be completed when it was opened to traffic in the summer of 2014.[12]