Traffic was backed up for several kilometres in the southbound lanes of Highway 400 Wednesday morning after a truck carrying a backhoe struck the Conc. 4 bridge in Innisfil.

The boom of the backhoe scrapped the underside of the bridge in the centre lane, hurling concrete onto the highway, OPP Const. Dave Woodford said.

Small pieces of concrete and debris landed on a car travelling behind the truck, but there was no damage or injuries, Woodford said.

“A motorist saw it happening,” Woodford said. “They didn’t think the truck was going to make it under so they backed off a little.

Woodford said the impact also jarred loose some concrete from another section of the bridge over the right lane that had been struck in the past.

The right and centre lanes were closed for several hours Wednesday morning as police waited for an engineer to inspect the bridge to make sure it was safe. Traffic was back up as far north as Mapleview Drive in Barrie.

The truck and the backhoe were taken to the McDonald’s parking lot at County Road 89, where a repairman was fixing hyrdraulics that were damaged when the boom hit the bridge.

It appeared the boom had not been lowered far enough after the backhoe was placed on the flatbed trailer, making the load too high to make it under the bridge.