U.S. Highway 171<!--La DOTD uses Highway--> (US 171) is a part of the United States Numbered Highway System and the only route within that system currently located entirely within the state of Louisiana. It spans |group=lower-alpha in a north–south direction from the junction of US 90 and Louisiana Highway 14 (LA 14) in Lake Charles to the junction of US 79/US 80 and LA 3094 in Shreveport.
As its designation indicates, US 171 is numbered as a spur of US 71, the principal north–south U.S. Highway through Shreveport, though they technically do not intersect. US 171 traverses six of the seven parishes along the Texas state line, the only exception being Cameron Parish located on the Gulf of Mexico south of Lake Charles. The route connects all six parish seats as it travels through the thick pine forests of western Louisiana on a wide four-lane right-of-way. The northern half of the route serves as the only major north–south corridor between Interstate 49 (I-49) to the east and the Toledo Bend Reservoir along the state line to the west. Between the metropolitan areas at each terminus, US 171 passes through the smaller cities of DeRidder, Leesville, and Mansfield, as well as the towns of Rosepine, Many, Zwolle, and Stonewall. Along the way, the highway has interchanges with many of the state's major east–west routes, including Interstate 10 (I-10), US 190, LA 28, US 84, and I-20.
US 171 was created as one of the original routes of the numbered U.S. Highway system in November 1926. Its only major alignment change occurred in 1937, when the highway was shifted from what is now LA 175 between Many and Mansfield. Improvements over the years have included the paving of the entire route during the early 1930s, the elimination of many at-grade railroad crossings during the remainder of the decade, and the widening of the highway to four lanes through its urban areas during the 1960s and 1970s. Four-laning of the entire route was accomplished between 1990 and 2010 via the state's massive TIMED program with the goal of improving safety and promoting economic development along the corridor.
The route carries several honorary designations, primarily that of the Purple Heart Highway in tribute to all recipients of the Purple Heart military decoration. The route has long been associated with the U.S. Armed Forces due to its proximity to at least four military bases active during the World Wars, the lone survivor of which is Fort Polk near Leesville.
Route description
Lake Charles to Leesville
From the south, US 171 begins at a junction with US 90 (Fruge Street) and LA 14 (South Martin Luther King Highway), in Lake Charles, the largest city in Calcasieu Parish and southwestern Louisiana. Traveling about east of the downtown area, US 171 continues the route of LA 14 northward along North Martin Luther King Highway, initially as a divided four-lane highway. After immediately crossing over the BNSF and Union Pacific (UP) railroad lines, N. Martin Luther King passes through a partial cloverleaf interchange with I-10 at exit 33, connecting with Beaumont, Texas to the west and Lafayette to the east. The highway gains a center turning lane and an additional northbound travel lane throughout the commercial corridor north of the interstate. Upon exiting Lake Charles, US 171 traverses a strip of wetlands with twin-span bridges over two navigable waterways, English Bayou and the Calcasieu River. After crossing the latter, the roadway remains elevated until reaching the unincorporated suburb of Moss Bluff. A junction here with LA 378 (Sam Houston Jones Parkway) leads west to Sam Houston Jones State Park and the nearby city of Westlake. US 171 maintains a combination of single and double center lanes through Moss Bluff, dropping the N. Martin Luther King Hwy signage as it passes just north of central Moses Bluff. As the surroundings become less developed, the right-of-way widens to accommodate a broad, grassy median.
North of Moss Bluff, a rural area known as Gillis introduces a mixture of open farmland, thick forest, and scattered residential development that characterizes the next to the city of DeRidder. During this stretch, US 171 enters Beauregard Parish and engages in a folded diamond interchange with US 190 and LA 12 that allows a grade separation with the Union Pacific Railroad line. Located in Ragley, the landscaped eastern side of the interchange doubles as a recreational area known as Purple Heart Memorial Park, echoing the official designation of US 171 as the Purple Heart Highway. US 171 proceeds due north from Ragley co-signed with US 190 through the community of Longville, located at the eastern terminus of LA 110, and enters the outskirts of DeRidder. Approaching the city limits, US 171 and US 190 pass the western termini of three rural state highways. The first, LA 394 leads to a recreational area on Bundick Lake. The others, LA 26 and LA 112, connect to Oberlin and Oakdale in neighboring Allen Parish.
Curving west into the parish seat, US 171 serves as DeRidder's main east–west commercial thoroughfare. Initially traveling along 1st Street with a center turning lane, the route divides into a one-way pair as westbound traffic transitions onto Mahlon Street. The highway then crosses the Kansas City Southern Railway (KCS) line into the downtown area, where it passes several historic buildings over the next few blocks. These include the Beauregard Parish Courthouse and an infamous Gothic structure known as the Hanging jail. US 171 ends its concurrency with US 190 by turning north onto Pine Street, an undivided four-lane thoroughfare. From this intersection, LA 27 heads south on Pine Street toward DeQuincy while US 190 continues west on the one-way pair of 1st and Shirley Streets toward Merryville. US 171 remains a commercial corridor until it crosses the Vernon Parish line, reverting to its rural configuration as it closely parallels the KCS rail line.
Leesville to Mansfield
In Leesville, US 171 becomes a busy commercial corridor again, initially traveling along 5th Street's narrow four-lane right-of-way. Another one-way pair is then utilized as the parallel 6th Street begins to carry southbound traffic. In the center of town, three state highway junctions are encountered in the space of a few blocks: LA 467 (University Parkway) to Northwestern State University's Fort Polk campus; LA 468 (Lula Street) to the historic business district; and westbound LA 8 (Nolan Trace Parkway) toward Jasper, Texas. US 171 proceeds north concurrent with LA 8 and descends below grade to cross under the KCS railroad line. Curving to the northwest, the highway's travel lanes converge as it approaches a roundabout. Here, at the northern end of town, LA 8 departs to the east and travels concurrently with LA 28 toward Alexandria, the principal city of central Louisiana. During its remaining in Vernon Parish, US 171 crosses the northeastern tip of Vernon Lake and passes through the rural towns of Anacoco and Hornbeck. Junctions there with LA 111 and LA 392, respectively, lead to points along the vast Toledo Bend Reservoir located on the Texas state line.
After crossing over the KCS Railway at Noble, US 171 curves back to the north and intersects LA 174 in the village of Converse. Closely following the rail line once again, US 171 crosses into DeSoto Parish just south of Benson, a point located at an intersection with LA 512. later, the highway makes an S-curve across the KCS line on a high twin-span overpass before proceeding due north into South Mansfield, a small village connected to the city of Mansfield, the parish seat. In Mansfield proper, US 171 follows Jenkins Street and intersects US 84 at Washington Avenue, connecting with Logansport to the west. US 84 overlaps US 171 for a short distance until reaching Polk Street, while the bypassed original mainline route follows the continuation of Washington Avenue signed as US 84 Bus. At Polk Street, signage points motorists onto eastbound US 84 toward the Mansfield State Historic Site, a Civil War battlefield, as well as the former Mansfield Female College, the first institution of higher learning for women west of the Mississippi River. US 84 also leads eastward to an interchange with I-49.
Shreveport metropolitan area
As it enters the Shreveport metropolitan area, US 171 begins to approach and eventually parallel the route of I-49, the state's major north–south highway. After curving northwest out of Mansfield, US 171 passes the DeSoto Parish Airport and heads through Grand Cane, located at a junction with LA 3015. later, the highway bends due north again and then crosses LA 5 at a junction in Gloster known as Kickapoo. Just before crossing into Caddo Parish, US 171 passes through the town of Stonewall and intersects LA 3276, a connector to I-49. Across the parish line, US 171 crosses underneath the Union Pacific Railroad tracks in the unincorporated community of Keithville. Residential development gradually increases as the highway parallels the UPRR line toward the Shreveport city limits.
US 171 enters Shreveport on Mansfield Road and retains its wide median as it becomes a heavily traveled commercial corridor once again. The highway has junctions with LA 525 (Colquitt Road), as well as LA 526, a major thoroughfare along the south side of town called the Bert Kouns Industrial Loop Expressway. Larger shopping developments line the roadway as US 171 approaches an interchange with LA 3132 (Terry Bradshaw Passway), a freeway loop commonly known as the Inner Loop Expressway. LA 3132 complements the I-220 northern bypass of Shreveport and connects to major interchanges with I-20 to the northwest and I-49 to the east. Some movements between US 171 and LA 3132 are accomplished through a connected interchange with Jewella Avenue, a divided thoroughfare that branches off of Mansfield Road. The posted speed limit ranges from throughout most divided rural stretches to as low as within some corporate limits. Decades earlier, two markers were installed on US 171 identifying it as a Blue Star Memorial Highway as "a tribute to the Armed Forces that have defended the United States of America." The first was dedicated on March 17, 1957 at the roadside park in Ragley. The second was dedicated on November 11, 1964 at the intersection with Washington Street in DeRidder.
Additionally, a stretch of US 171, extending from LA 26 south of DeRidder to LA 10 south of Leesville, serves as part of the Myths and Legends Byway in the state-designated system of tourist routes known as the Louisiana Scenic Byways.
History
Original route and early improvements
US 171 was designated in November 1926 as one of the original routes of the numbered U.S. Highway system. The majority of the route, extending from Lake Charles to Many, has remained largely unchanged to the present day. North of Many, however, US 171 was initially routed along the current LA 175 to Mansfield, where it rejoined the modern alignment into Shreveport. The entire route was also initially co-signed with Louisiana's corresponding state highway designations as created in 1921. These consisted of State Route 42 from Lake Charles to Many, State Route 51 from Many to Belmont, and State Route 1 from Belmont to Shreveport.
Upon its designation in 1926, US 171 was generally a gravel road outside the city of Shreveport. Instead, the modern alignment via Zwolle, which was also the northern portion of Route 42 prior to 1955, was being straightened and paved to serve as US 171. The revised route also received two grade separations with the Kansas City Southern Railway line that were constructed in 1934. These consisted of an overpass at Noble and an underpass at Trenton, about south of Mansfield. Completed at the end of 1937, this would be the only major alignment change in the highway's history and the only instance in which the paved alignment significantly differed from the established gravel road. Minor deviations, mostly near the highway's southern end, included a diagonal cutoff that bypassed a section line road zigzag running northwest from Gillis and the straightening of the route through Longville.
During the mid- to late 1930s, six additional grade separations were constructed elsewhere along US 171, eliminating nearly every railroad crossing along the route. The first was an overpass of the now abandoned Gulf, Colorado and Santa Fe Railway just east of DeRidder in 1934. The others were constructed beginning in 1935 as part of a federally funded grade separation program. That year, $3.2 million was allocated for this purpose by a Works Progress Administration program and was earmarked by the Louisiana Highway Commission for 28 separate projects. Those projects along US 171 consisted of overpasses of the Southern Pacific Lines at Lake Charles, the Gulf Coast Lines at Ragley, and the Texas and Pacific Railway at both Grand Cane and Shreveport, as well as an underpass of the Kansas City Southern at Leesville. The overpasses were all completed in 1937, with the Leesville underpass following in 1939. All have since been replaced or supplemented with newer four-lane crossings, except the DeRidder and Grand Cane structures, which have been eliminated due to abandonment of the railroad lines.
Urban improvements and initial widening projects
The next burst of activity in improving US 171 occurred in Caddo Parish, where the entirety of Mansfield Road from the DeSoto Parish line to LA 511 in Shreveport was reconstructed and straightened beginning in 1951. Several sections of the original roadway still exist as local roads, now re-named as Old Mansfield Road, that weave in and out of the current alignment. Additionally, the portion from Southland Park Drive to Jewella Avenue now serves as a frontage road to the modern route. The project was completed in 1954 at a cost of $1,921,000. The new alignment also included an underpass of the Texas and New Orleans Railroad line at Keithville, replacing the grade crossing there. In 1959, the final alignment change in Shreveport had US 171 transition from Mansfield Road onto Hearne Avenue to reach its northern terminus, giving the highway its first section of four-lane pavement. Around 1965, two additional lanes were built on Mansfield Road extending south to LA 526. This was roughly concurrent with the opening of the I-20 interchange on Hearne Avenue, connecting US 171 with the new expressway through Downtown Shreveport and improving access to the US 80 corridor east of the city. The highway was then widened southward through the Keithville area in 1967, making US 171 four lanes throughout both the city of Shreveport and Caddo Parish.
The opposite end of US 171 received its first section of four-lane pavement in the early 1960s when the roadway was widened in Lake Charles between the southern terminus at US 90 (Broad Street) and Fruge Street. and the southern terminus of US 171 was shifted accordingly. The I-10 interchange on US 171 was partially opened to traffic at this time. Its full opening would occur in February 1964 when the interstate was completed eastward to US 165 at Iowa. In the mid-1960s, four-lane sections of US 171 were also opened to facilitate traffic through two smaller cities. In Mansfield, Washington Avenue was widened and extended southwest, improving the routes of both US 84 and US 171 through town and eliminating two right-angle turns. This was necessitated by an impoundment of the creek four years earlier that created the recreational Vernon Lake. A more substantial project completed in 1969 overhauled the two most significant water crossings on US 171, the English Bayou and Calcasieu River bridges between Lake Charles and Moss Bluff. The original narrow two-lane spans dating from the 1920s were replaced with four-lane spans on a new four-lane alignment further west. (Though the bridges were demolished in 1973, the land portions of the route still exist as Old US 171, partially as local roads leading to public boat launches and partially on private property.) In 1972, the remaining gap in the four-lane alignment in Lake Charles between Fruge Street and the new bridge approach was widened. Central to this project was the twinning of the railroad overpass south of I-10.
Completing the four-lane highway
Since the 1970s, construction projects on US 171 have mainly focused on completing the highway to four-lane capacity throughout its entire length. This was cited by commercial and political interests as crucial for the economic development of the corridor and a necessary step in preventing the loss of economic opportunities to the US 59 corridor in East Texas. Leesville was the last urban area through which the highway was widened, despite the Army personnel at Fort Polk having pushed the Louisiana Department of Highways for this improvement over several decades. Four-lane segments through the Leesville area were completed approximately as follows: through New Llano and north toward LA 467 in 1975, south from New Llano toward Pickering in 1978, further south to DeRidder in 1981, and finally northward through the city of Leesville in 1982. This last segment involved the creation of a one-way pair using an improved 6th Street to carry southbound traffic and the construction of a parallel railroad underpass. US 171 was further widened northward from Leesville to Anacoco in 1986. Meanwhile in Shreveport, the highway was widened southward from the Caddo–DeSoto parish line through Stonewall in 1981, joining with the four lanes extending from there to LA 5 in Gloster constructed in the late 1970s. After falling far behind schedule by the late 1990s, the legislature approved the first of several bond measures to fast-track the program. The widening of US 171 was divided into 23 projects totaling approximately and carried out between 1990 and 2010. As before, the four-lane alignment mostly followed the established two-lane with minor deviations to straighten various curves in the roadbed. This is most evident between Mansfield and Grand Cane, where the entire route was reconstructed and straightened.
However, more significant changes were carried out in a few locations. A new route through Many bypassed the downtown area, discontinuing the concurrency with LA 6. The neighboring town of Zwolle was bypassed altogether with a new alignment constructed around its northeast side. In this case, the old route through town was retained as US 171 Bus., which was designated in 2008. The route through Mansfield was also streamlined via the widening and extension of Jenkins Street, which benefitted the concurrent US 84 as well. Here, the original four-lane section of Washington Avenue was retained as US 84 Bus.
The latest improvement to US 171 involved the installation of a roundabout at the northern end of Leesville. It was the first roundabout to be constructed in the seven parishes forming the state highway department's District No. 8. Located at the junction with eastbound LA 8/LA 28, the junction was previously a signalized T-intersection that was the site of numerous accidents and frequent traffic pileups. Construction began in October 2010, and the project was completed with a ribbon-cutting by Governor Bobby Jindal on August 5, 2011 after an expenditure of $2.1 million.