Межштатная автомагистраль I-49: маршрут от Луизианы до Канзас-Сити.

Interstate Highway in Louisiana, Arkansas, and Missouri

I 49 in Arkansas is composed of three disconnected segments: northern, southern, and a short connector skirting Fort Smith near Fort Chaffee that is currently designated as AR 549. The southern segment of I 49 enters Arkansas from Louisiana. The short segment progresses northward to a temporary terminus at US 71 and US 59 at the Texas state line north of Texarkana. The northern segment of I 49 in Arkansas, most of which was formerly signed as part of I 540, begins at I 40 in Alma and runs north to Northwest Arkansas through the Boston Mountains. The freeway passes through steep, sparsely populated terrain before entering the Bobby Hopper Tunnel in Washington County. Entering Northwest Arkansas, I 49 has seven exits for Fayetteville and three exits for Springdale before entering Benton County. The route serves as the boundary between Bentonville and Rogers, with seven exits for the two cities. After an interchange with US 71 just south of the Bentonville–Bella Vista city line, I 49 follows the Bella Vista Bypass, which runs to the south and west of Bella Vista before crossing into Missouri. I 49 is designated as the Boston Mountains Scenic Loop between Alma and Fayetteville. The I 49 designation replaced the I 540 designation through Northwest Arkansas in March 2014, with the exception of the Bella Vista Bypass, which was constructed between July 2011 and October 2021.

I 49 enters Missouri from Arkansas on the Bella Vista Bypass, eventually reuniting with US 71 south of Pineville. Continuing northward, I 49 passes through several smaller communities, including Neosho, before reaching Joplin. In Joplin, I 49 junctions with I 44 and begins a short concurrency with I 44 for exits 11 through 18. Just a few miles east of Joplin, I 49 leaves I 44 and heads north and enters Carthage, intersecting with Interstate 49 Business (I 49 Bus. )/Route 171, which provides an alternate route for northbound I 49 travelers through Joplin. I 49 then passes through Nevada and other communities before reaching the Kansas City area. I 49 intersects with I 470 and I 435, which provides connection to I 70, I 35, and I 29. In south Kansas City, at Bannister Road just north of the Grandview Triangle, the I 49 designation ends, and the freeway continues as Interstate 435 north to I 70 west and the expressway continues as US 71, which proceeds into downtown Kansas City as Bruce R. Watkins Memorial Drive.

The original plans for the Interstate Highway System did not include a north–south connection between I 10 and I 20 within Louisiana. In 1965, Governor John McKeithen proposed a toll road to perform this function and extend it to New Orleans as well, but the idea was never carried out. In the mid 1970s, the Federal Highway Administration (FHWA) approved an Interstate Highway to run between US 190 in Opelousas and I 20 in Shreveport, a route that was designated as I 49 by the American Association of State Highway and Transportation Officials (AASHTO) in the summer of 1977. The mileage was gained from mileage released from other highways the states did not build as well as 153 mile (246 km) from a supplemental reserve. In its early history, I 49 was commonly referred to as the North–South Expressway. This segment joined the portion running concurrent with US 167, an existing limited access highway, and was completed by 1983. By the following year, virtually all remaining rural portions of the route were under construction, and 95 percent of this mileage was completed and opened to traffic between late 1987 and late 1989. The remaining portions running through the urban centers of Alexandria and Shreveport required a much greater expenditure of time and funding. The entire length of the 212 mile (341 km) road was completed on May 1, 1996, with the opening of a 16.6 mile (27 km) section in downtown Alexandria named the Martin Luther King Jr. Highway. The total cost of I 49's construction was about $1.38 billion (equivalent to $ in ). On May 31, 2017, a 4.25 mile (7 km) portion between LA 3194 (Martin Luther King Jr. Drive) and LA 1 in Shreveport was opened to northbound traffic. On June 15, 2018, the entire 5.25 mile (8 km) portion of I 49 between I 220 and LA 1, including an interchange with I 220, was opened to traffic. The remaining interchange ramps opened to traffic on October 17, 2018.

Arkansas and Missouri pursued an I 49 designation for US 71 and I 540 for many years. In the early 2000s, there were plans by both states to rename the roadway as such between I 44 west of Joplin and I 40 at Fort Smith once a new bypass of US 71 had been completed around Bella Vista, Arkansas, and north to Pineville, Missouri. The designation applies to current US 71 between I 435 in south Kansas City and Route H at Pineville (McDonald County), which was expanded to Interstate standards beginning in 2010. The last of the expansion projects was completed in December 2012. I 49 also runs concurrently with I 44 between exits 11 and 18 east of Joplin. The Missouri Department of Transportation (MoDOT) began installing I 49 trailblazer signage (without shields) along with gantry signs and milemarkers, about 1200 signs in all, in February 2012. Signage bearing I 49 shields was covered or turned from view until the I 49 designation received final approval by FHWA. This includes milemarkers at 0.2 mile (0 km) intervals along the entire alignment apart from I 44. MoDOT announced the Joplin to Kansas City expansion of US 71 in August 2010, to be done with the intention of bringing the I 49 designation to Missouri. was built to Interstate standards. However, three at grade intersections—at Gregory Boulevard (71st Street), 59th Street, and 55th Street—prevent the I 49 designation from being extended all the way to downtown. All three of these intersections were on the Kansas City Police Department's 2010 list of "Top 20 Crash Sites in Kansas City", at #9, #6 and #4, respectively, and Watkins Drive has the reputation among commuters as "one of the city's most accident prone stretches of road". a parkway which directly connects the I 70/I 670 interchange in downtown Kansas City, as well as the I 35/I 29/I 70 interchange just to the north, to south Kansas City and I 435, I 470, and I 49. I 130, a former future designation from 2000 to 2014, was removed and no longer exists as part of the Texarkana Loop.

A temporary designation of AR 549 had been assigned to I 49 between US 71 north of Texarkana and Doddridge, 5 mile (8 km) from the state line. I 49 has now been completed to the state line. "Future I 49" segments extending northward from Texarkana, Arkansas, plus segments from Doddridge south into Louisiana were shown on the official Arkansas 2013 Highway Map. The route was completed and signed as I 49 in late 2014.

North of I 40, I 49 previously ended south of Bella Vista prior to October 1, 2021, about 8 mile (13 km) south of the Missouri state line. Travelers were forced to travel north on 15 mile (24 km) of four lane US 71 with intersections, traffic signals, lower speed limits, and congestion before the present northern segment of I 49 began at Pineville, Missouri. The completion of the 19 mile (31 km) "Bella Vista Bypass" between Bella Vista, Arkansas, and Pineville, Missouri filled the gap and made I 49 a continuous route from Kansas City to Alma, Arkansas. A major hurdle to the construction of the bypass over the years was funding. The 2010 TIGER grant application submitted by the Arkansas Highway and Transportation Department (AHTD) estimated the total cost for completion in Arkansas as $291.8 million (equivalent to $ in ). The document states the portion of the bypass in Arkansas is "proposed to be constructed as a toll facility, while the Missouri portion of the Bypass will be constructed as a free route". On August 11, 2010, the US Department of Transportation (USDOT) announced $10 million (equivalent to $ in ) in Transportation Investment Generating Economic Recovery (TIGER) grant funding to construct a portion of the new four lane bypass, though the funding covered only a two lane segment 2.5 mile (4 km) long. Groundbreaking occurred on July 8, 2011, with a public ceremony that included Transportation Secretary Ray LaHood, Arkansas Governor Mike Beebe, and Senator Mark Pryor. The USDOT news release refers to the project as part of the "I 49 corridor", effectively ending questions about how the new highway would be numbered. The following year, the segment between AR 72 north and County Road 34 was let. In March 2014, AHTD anticipated completion of this first segment between AR 72 north and AR 72 south in spring 2014, and the next section in autumn 2014. However, AR 549 between AR 72 and County Road 34 was not completed and opened until August 22, 2015. Following the passing of a ten year half cent sales tax measure in 2012, AHTD had acquired sufficient additional revenue to fund the southbound half of the Bella Vista Bypass without tolls. Since design work had been completed prior to passing the measure, AHTD was able to let the segment between AR 72 and U. S. Route 71 Business (US 71B) in February 2014 as the first job of the Connecting Arkansas Program. AHTD anticipated completion of this project in 2016. However, once Arkansas began building toward the state line, it was revealed that Missouri was $25 million (equivalent to $ in ) short of the necessary funds to complete their section. A ballot initiative was defeated in August 2014 in Missouri, which put the project on hold for nearly five years. The only Arkansas project remaining for a fully operational two lane bypass was the 7.6 mile (12 km) section between County Road 34 and the Missouri state line; however, was is listed as TBD by AHTD. Construction on the interchange was tentatively scheduled to be complete in 2018. On May 10, 2017, a 6.4 mile (10 km) segment of the bypass between the existing 5 mile (8 km) segment near Hiwasse, Arkansas, and a new temporary roundabout interchange with I 49 and US 71 near Bentonville, Arkansas, opened after three years of construction and costed over $50 million (equivalent to $ in ) to complete. In March 2019, the Missouri Highways and Transportation Commission approved funding for the completion of the Bella Vista Bypass. Construction bids were approved in early April 2020, and construction was expected to finish in Arkansas by late 2021. The remaining 4.8 mile (8 km) in Missouri were also slated to be completed by late 2021. Once Missouri completed this portion, the gap closed, and four contiguous lanes of freeway from the Kansas City region to Alma, Arkansas, near the Fort Smith area was completed. The Bella Vista Bypass opened to traffic on October 1, 2021.

The Louisiana Department of Transportation and Development (DOTD) is working to extend I 49 from Lafayette southeast to New Orleans along the route of US 90, which is a divided four lane highway between the two cities. This segment is listed under High Priority Corridor 37. Some portions, such as the freeway between Morgan City and the Raceland area, are already built to Interstate standards. In the Lafayette area, the project is divided into two projects, the I 49 Lafayette Connector and the expansion of US 90 from Lafayette Regional Airport to the LA 88 interchange. The I 49 Lafayette Connector underwent a Supplemental Environmental Impact Statement study and Conceptual Design Study due to refinements to the alignment originally approved in the February 2003 Record of Decision. It is planned to be a six lane elevated freeway, mostly utilizing the Evangeline Thruway corridor, except for a segment paralleling the BNSF/Union Pacific railroad line to serve the downtown area. Planning for this segment has been ongoing for decades, but construction has been delayed numerous times due to local opposition. The most recent attempt to begin construction was halted due to federal officials launching a civil rights investigation into the project in early 2023. The rest of the freeway from the airport to LA 88 will be an at grade six lane freeway with a 2 mile (3 km) segment of eight lane elevated freeway through the suburb of Broussard. Work on this segment began on November 15, 2022. US 90 between LA 88 and LA 182 west of Wax Lake is already widened to Interstate standards, including a former at grade intersection with LA 318 south of Jeanerette, which was converted to a grade separated interchange with frontage roads for local access. From Wax Lake to the Atchafalaya River bridge at Morgan City, US 90 is a four lane divided at grade expressway. A Supplemental EIS is ongoing to expand that segment to interstate standards. The Raceland–New Orleans segment of the proposed I 49 South was originally approved in 2008 with a Record of Decision for a fully elevated freeway on a mostly new alignment along the entire length. However, in 2014, DOTD launched a study to consider less expensive alternatives and to expedite design and construction of that segment. The resulting design changes greatly reduced costs by incorporating much of the existing US 90 corridor, save for bypasses of Des Allemands and Paradis, as well as a revised connection with I 310/LA 3127. A Supplemental EIS is ongoing for that segment to finalize these changes. In the immediate New Orleans area, I 49 is planned to follow the route of US 90 Bus., much of which is an elevated freeway. US 90 Bus. follows the Westbank Expressway through Westwego, Gretna, and Algiers. It then crosses Crescent City Connection over the Mississippi River into Downtown New Orleans and continues onto the Pontchartrain Expressway to an interchange with I 10. "Future I 49" signage is visible along US 90 and US 90 Bus., although, as of 2017, construction has yet to begin.

In addition to the southern extension, Louisiana officials are also working on the completion of I 49 from Shreveport to the Arkansas state line. Options for the remaining gap between I 20 and I 220 in Shreveport include the proposed Inner City Connector, a 3.6 mile (6 km) direct connection between the completed portions of I 49. A no build proposal is to reroute I 49 onto existing portions of LA 3132 (Inner Loop Expressway) and I 220 through Shreveport. Opposition regarding the direct routing through the historic Allendale neighborhood led to new proposal that would also provide a direct connection to the completed I 49, but loop around the neighborhood instead of going through it. The proposal was made public on January 20, 2023, but public opposition to the connector remains strong.

North of Texarkana, I 49 will briefly venture into Texas for about 5 mile (8 km) before turning northwest and crossing the Red River of the South to re enter Arkansas. How the mileposts and the exits will be numbered once the Interstate returns to Arkansas have yet to be determined and TxDOT currently has no plans to construct this segment.

The 180 mile (290 km) section between Texarkana and Fort Smith remains largely incomplete. Right of way has been acquired and engineering has been completed, but construction is contingent upon allocating funding to the corridor. After applying for and receiving assistance from the 2012 TIGER grant program, ArDOT began construction on the new path for I 49 towards US 71 south of Fort Smith, bypassing Van Buren and Fort Smith. Work is now complete between US 71 and AR 22 near Fort Chaffee as the first and southernmost phase of the extension of I 49 bypassing I 540. The project is explicitly mentioned as an effort to complete I 49 in the TIGER grant application. Colloquially referred to as "Chaffee Crossing", this first phase was completed on July 15, 2015, at the AR 549 and AR 22 Interchange A groundbreaking on the segment to I 40 occurred on October 13, 2022; this segment is estimated to cost $800 million, almost half of which is going to the bridge over the Arkansas River. Construction on this project will start in early 2024 and last five to six years. South of this segment, I 49 is planned to follow the general route of US 71 through the state between I 30 and I 40.