A motorway overbridge has been struck by over height vehicles twice in the same weekend, prompting urgent maintenance
works, just a year after major repairs following similar incidents.
“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,” says Waka Kotahi Auckland Systems Manager Andrea
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,” says Andrea Williamson.
Current guidelines stipulate the maximum height for a load is 4.3 metres, with over-dimension permits required when a
load exceeds five metres. However, 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.
Waka Kotahi is calling on heavy haulage operators and independent excavator companies to make sure drivers are aware of
their surroundings or warn they risk being ticketed.
“We know the Penrose overbridge is one of region’s most restrictive, which is why we have installed additional safety
features including electronic signs to warn drivers who risk hitting the bridge. It’s disappointing when those alerts
are ignored as it puts the road user at significant risk of serious injury and death,” says Andrea Williams.
“Repairing bridges from this type of event is costly and often requires motorway closures disrupting travel for other
In 2018 a protective steel beam was installed in front of the bridge above both the northbound and southbound lanes. The
beams are to work in conjunction with the over height detection system and signage. Following yet more strikes, the
bridge plate was last year removed in sections for repairs to be undertaken. That revealed more damage than expected,
with the overbridge needing to be partially closed until the bridge capacity was restored.
“Now further repair works will again be required in the weeks ahead, to restore damaged concrete as well as testing to
identify any cracking or fatigue. We will advise road users of any closures ahead of time,” says Andrea Williamson.
Waka Kotahi will also be sending out measuring tools and guidelines to operators to ensure drivers know the rules before
setting out.Plan ahead for a safe, enjoyable journey. Keep up to date with:COVID-19 services update: nzta.govt.nz/COVID19
Traffic updates: journeys.nzta.govt.nz/traffic
Facebook Auckland: facebook.com/nztaakl
Facebook Northland: facebook.com/nztanorthland
Journey planner: journeys.nzta.govt.nz
Phone: 0800 4 HIGHWAYS (0800 44 44 49)