Highway 78 is a designation for two state highways in the Arkansas Delta. One route of 24.03 miles (38.67 km) begins at Highway 306 near Hunter and runs southeast to US Highway 79 (US 79). A second route of 4.30 miles (6.92 km) begins at Highway 121 and runs west to a junction with Lee County Route 132 (CR 132) and CR 173. A short spur route in Moro, Highway 78 Spur connects the parent route to Highway 238. All routes are maintained by the Arkansas State Highway and Transportation Department (AHTD).

Highway 306 is a designation for three east–west state highways in the Arkansas Delta. One segment of 6.65 miles (10.70 km) runs from Highway 38 in Cotton Plant north to Woodruff County Road 680 (CR 680) at Becton. A second segment of 24.27 miles (39.06 km) runs northeast from US Route 49 (US 49) in Hunter to Highway 284. The third segment runs 5.98 miles (9.62 km) east from Cross CR 825 at the St. Francis River to Highway 75 at Gieseck.