Major payment reconstruction from I-40 mm 275 to mm 279 in West Memphis. Total pavement replacement (digging down 3 feet) plus bridge deck rebuilding. This is the section in W Memphis that is both I-40 and I-55. Single lane only in both directions.
One option is get off at mm 271 and take US 70/79 (Broadway) thru W Memphis, which becomes I-55, cross the Miss River on the I-55 bridge, then follow I-240 to return I-40.
if you go thru Memphis, you will hit another bottleneck at the east edge of the city, where I-40 meets I-240 - single lane with construction of new flyovers and replacement of bridges. The project began Nov 2013, may take up to 4 years to complete.
Good luck.