Drivers heading toward Iowa Street from McDonald Drive on Thursday will be steered onto a detour to avoid a pothole — actually, a crew repairing a pothole.

From 9 a.m. to 2 p.m., workers from the Kansas Turnpike will close the short tunnel used by traffic going south on McDonald, underneath Sixth Street.

That’s to enable repairs to the damaged road base in the tunnel, known in engineering circles as a box culvert.

“We’ve got potholes that have developed down there,” said Rex Fleming, a turnpike project engineer. “That’s a real tight spot to work, so we need to get in there, get the work done and get it back open that afternoon.

“We just want to make people aware, so they don’t get frustrated.”

Drivers heading toward Sixth on McDonald will be directed to turn right onto Rockledge Road. Then, after going up the hill to the traffic signal on Sixth, they will be able to turn left onto Sixth and get back to Iowa Street.