You’d expect a smooth ride on a new four-lane highway, but that new pavement will be getting the jackhammer. A short section of Highway 31 north of Gretna will have to be repaved.

A wider Highway 31 cost millions of dollars, so taxpayers don't expect a dip in their investment. "It's quite a dip,” says driver Karen Zona. “I’ve seen people pretty much bottom out around there."

Settling of the soil around a new culvert created a dip on Highway 31 near Giles. It's worse on the southbound side as vehicles take a little bounce that might startle some drivers. "If you hit it it's like kind of going over a little roller coaster," says driver Nancy Suhr.

You hope hitches and chains hold tight on vehicles hauling trailers over the dip that does have plenty of warning signs. "We're going to have to replace some pavement out there,” says Marve Lech with the state roads department.

“It's not something the contractor did wrong. You don't know what's down everywhere. It's a Mother Nature thing."

After several soil tests, state engineers say the culvert and highway on top of it don't appear to be sinking any longer. Though state engineers are confident the settling has stopped, until that pavement is replaced and area smoothed out, they suggest drivers slow to 45 mph.

“It's a hazard if people don't keep their speed down,” says Lech. “If they keep it down to reasonable nothing is going to happen to anybody."

Zona, who lives near the dip, doesn't see many following the suggested lower speed. "Nobody does 45 out here. Now they've opened it they're doing 70 out here."

State engineers say the southbound lanes will be smoothed over before winter. Until then drivers should slow when they see the warning that a dip in speed is recommended.

We won't know what this unexpected settling will cost taxpayers until bids come in. One-hundred-twenty-feet of pavement will be replaced.

Tthe southbound lanes of Highway 31 will not be closed. Traffic will likely cross over, creating a two-lane stretch until the repairs are done.