On the day of the Minneapolis 35W bridge collapse, Burleigh County engineer Jon Mill received a call that the rides on the McKenzie haul-road bridge were getting rough.

An inspection showed that, indeed, there was movement in the three-span bridge, according to Mill. The cap on the north pier of the middle span was deteriorating, causing the load to shift.

The road is located just off of Interstate-94's McKenzie Exit about 17 miles east of Bismarck. The road parallels the interstate for about two miles, then turns north. The bridge is located about five miles north of the turn.

A quick repair was put in place, shoring up the pier cap, but further inspection of the pier found greater problems, as the treated timber forming the pier was rotting.

A temporary pier was put in place to shore up the bridge, but Mill wants to replace the entire 42-year-old, 84-foot structure next summer. He's roughly estimating the cost at $400,000.

The bridge gets frequent use, with 200 to 300 trucks heavily loaded with aggregate crossing it each day, Mill said.

"The problem is, the trucks are killing us with the type of loads they carry and the frequency they use it; that's tough," Mill said. "We're trying to keep the loads to 80,000 pounds gross weight, but the customers are using more weight."

Mill maintains that loads greater than 80,000 pounds also are tough on the county's roads. Carriers argue that, with more axles, the weight is spread out over the road, which the county engineer doesn't quite buy into. Mill said he knows that doesn't apply to bridges when the entire load, no matter the weight, is supported by the structure alone.

Signs have been put up reminding drivers about the weight restrictions, and the speed limit over the bridge has been reduced to 15 mph, but not all vehicles have been slowing to that, Mill said.

Some vehicles were even parked at either end of the bridge in an attempt to get trucks to slow down.

There are federal funds available for bridges, but the amount is limited and determined by a bridge's rating. Mill said he is fairly sure the Burleigh bridge will have a rating low enough to compete with most bridge projects in the state, but most of the projects for 2008 have been set and he's not sure if funds will be available for the McKenzie bridge.

If there is, the federal government will pick up 80 percent of the cost. If not, the county will have to take on the burden by itself. Mill said there is a lot of competition for the bridge money.

Mill will put the replacement bridge in the 2008 Burleigh County budget. He said he expects the county will hold its regular meeting in January to prioritize road projects for 2008, and it's likely the bridge will move to the top of the list.

Other than the trucks hauling aggregate, the road gets little use, Mill said. There is some rural activity as farmers move their equipment to the fields.

"Right now, there is no real danger and I'm comfortable with the precautions we've taken," Mill said. "We're monitoring it regularly to see if there is any move in a deck relative to the others. It's pretty much under control."

Mill said he will be doing a hydraulic check, and hopes to replace the bridge with a multi-barrel box culvert that he believes provides the greatest stability and the fewestproblems.

"This is a unique situation. The truck hauling didn't really start taking place until about 10 years ago, but it's really been taking a toll. The frequency of loading is much more than it was designed for," Mill said. "I remember appearing before the Legislature, trying to prohibit the gross truck load creep we've been seeing. Some of those loads are 105,500 pounds, and the counties are hard pressed to meet those kind of weights."

(Reach reporter Gordon Weixel at 250-8255 or gordon.weixel@;bismarcktribune.com.)