State Road 678 (SR 678) is a 0.501-mile (0.806 km) stretch of Bearss Avenue between (Business US 41 (U.S. Route 41 Bus.)

State Road 678 has its western terminus at an interchange with US 41 Business.

Immediately the roadway widens to 6 lanes as it begins its eastern route.

[3] The state road along its entire stretch goes through a commercial district with numerous strip malls.

[5] State Road 678 continues through the shopping district before each its eastern terminus with US 41 after .2 miles.