Sometime in late 2018, ARDOT will open the first section of the US 412 Bypass around Springdale. The first section, approximately 4 1/2 miles will run from AR 112 near Cave Springs to I-49 near Lowell. The only reason it's being built first is because the Northwest Arkansas Regional Airport (XNA) wants to build a private toll road from the bypass to the airport.
According to ARDOT the new highway will be designated AR 612, to be replaced eventually by US 412 once the bypass is complete sometime in 2019.
Of course, construction also continues on AR 549/Future I-49 northwest of Bentonville. ARDOT recently announced plans to begin building the other 2 lanes from US 71at Bentonville to Benton County 34/ Rocky Dell Hollow Rd near Bella Vista. That would leave roughly 5 miles to be completed to the Missouri State Line, then 5 more miles to Pineville, Missouri connecting with the other section of I-49.