Oklahoma state line to North Little Rock

I-40 enters Arkansas from Oklahoma at Dora in Crawford County.^[2] It heads east into Van Buren, giving access to Fort Smith as well across the Arkansas River to the south. Access is primarily via I-540/US 71, which was built as a southern spur to Fort Smith in the 1970s. I-40 overlaps with US 71, forming a concurrency until the alignment of I-49 breaks north to Fayetteville, Springdale, Rogers, Bentonville, and its northern Arkansas terminus in Bella Vista, with US 71 breaking away shortly afterward at another interchange.^[3][4] The route continues to parallel US 64 into the Ozark Mountains by entering Franklin County and providing access to the Pig Trail Scenic Byway in Ozark.^[5] I-40 runs through Clarksville (where it has a junction with US 64), passes over part of Lake Dardanelle, and meets Highway 7 (AR 7) in Russellville.^[6][7] I-40 continues to the east through Morrilton before turning south to Conway and Faulkner County.^[8][9] In Conway, I-40 forms a concurrency with US 65 at exit 125, which continues until exit 153A in North Little Rock. The highway also has another junction with US 64 and U.S. Highway 65 Business (US 65B) in Conway before passing Lake Conway and entering the Little Rock metropolitan area.^[9]

North Little Rock to the Tennessee state line

Now in Pulaski County, I-40 heads toward the south-southeast as it heads to the town of Maumelle. It continues toward this direction until it reaches I-430, which provides access along the westside of Little Rock.^[10] Further southeast near the Arkansas River, the route has a high volume interchange as the northern terminus of I-30 as well as concurrent routes with US 67/US 167; US 65 turns south at this intersection, breaking the concurrency formed in Conway.^[10] I-40 (now concurrent with US 67 and US 167) continues east for 1.5 miles (2.4 km) before the latter two routes branch off to the northeast with I-57. From this point onward, I-40 begins to parallel US 70 rather than US 64, which was a more or less a parallel route until Conway. The Interstate continues to the east to intersect I-440 before entering Lonoke County.^[10] Passing through Lonoke, the route runs through rural Arkansas with straight alignments and relatively few junctions, forming an overlap with US 63 in Hazen until meeting US 49/AR 17 in Brinkley.^[11][12][13] Upon entering St. Francis County, I-40 runs northeast to Forrest City, where it intersects with AR 1.^[14] Continuing northeast, I-40 enters Crittenden County, where it intersects with US 79 at Shearerville and enters West Memphis.^[15]

The highway continues to the northeast to an interchange with I-55, and the two routes form a concurrency east for 3.1 miles (5.0 km). I-40 continues east onto the Hernando de Soto Bridge over the Mississippi River. The Tennessee state line is at the midpoint of the river, and Memphis, Tennessee, begins at the eastside of the bridge.^[15]