Waka Kotahi New Zealand Transport Agency is urging heavy haulage operators and independent excavator companies to be more aware of their surroundings while on the road or risk being ticketed.

The call comes after a motorway overbridge was struck by over-height vehicles twice in the same weekend.

The damage prompted urgent maintenance works, just a year after major repairs were undertaken following similar incidents.

Waka Kotahi Auckland Systems Manager Andrea Williamson said on both occasions warning signs were illuminated, but the vehicles didn’t reduce their speed, striking the bridge at speeds up to 100km an hour.

“It’s fortunate that nobody was hurt,” she said.

“Visible damage was immediately identified by responding crews, with a structural inspection and emergency works carried out to remove concrete debris from roadway.”

Maintenance to the collision protection beam was also needed to ensure full capacity of protection was restored.

“There’s been a marked increase in the number and severity of incidents in the last two years, and that’s why we will be working more closely with police to ensure the drivers are adhering to height restrictions,” Williamson said.

Current guidelines stipulate the maximum height for a load is 4.3m, with over-dimension permits required when a load exceeds five metres. All loads over 4.3m height require written approval from Waka Kotahi for all bridges spanning over motorways.

The Penrose Road overbridge, which is 4.57m above the road, has been struck 43 times over the last decade, severely damaging the main deck beams.

“We know the Penrose overbridge is one of the region’s most restrictive, which is why we have installed additional safety features including electronic signs to warn drivers who risk hitting the bridge,” Williamson said.

“It’s disappointing when those alerts are ignored as it puts the road user at significant risk of serious injury and death.”

She said repairing bridges from this type of event is costly and often requires motorway closures disrupting travel for other road users.”

Waka Kotahi will be sending out measuring tools and guidelines to operators to ensure drivers know the rules before setting out.