One route of 11.20 miles (18.02 km) runs from Interstate 57 (I-57) in Cabot north to Highway 38 east of Austin.

The route intersects Highway 89 in south Cabot before exiting the city and running due east.

A 2010 study of annual average daily traffic (AADT) by the Arkansas State Highway and Transportation Department (AHTD) reveals that about 19,000 vehicles per day (VPD) use the route between its southern terminus and Highway 89/Highway 367, with the traffic count dropping to 7,000 VPD between that junction and the Cabot city limits.

The route runs north, having a junction with Highway 321 Spur and passing through Essex.

Media related to Arkansas Highway 321 at Wikimedia Commons