Truckies are flouting weight restrictions on some of Christchurch's worst earthquake-damaged bridges.

In one case a driver in his early 20s was caught crossing a bridge with a 3.5 tonne limit in a vehicle weighing almost six times that. He was fined the maximum infringement of $10,000.

Constable Brian Pitt said the man's excuse was that he was following his GPS to go to his next location.

The man was one of 40 truck drivers caught crossing the Bridge St or Gayhurst Rd bridges in Dallington since July 5 last year. Both have a 3.5 tonne limit, which is clearly signposted.


Sergeant Max Newman, of the police commercial vehicle investigation unit, said most trucks caught were within the four to seven-tonne category but others weighed 14-15 tonne.

"The bigger they are the more risk there is. They're pretty sturdy but the problem is the damage is such that no one knows what might happen if you do take that risk.

"For them to go over the bridge they've driven past two or three signs that say it's a 3.5 tonne restricted bridge.

"Some of them do it because it's a convenient and quick way to get to where they're going and ignore the risk they're taking."

Sergeant Newman said drivers were putting their lives at risk - as well as the lives of others.

"Should any these bridges fail, there would be serious risk of death or injury to the public. The local residents would also be adversely affected with significant detours imposed on all road users who use these bridges."

The weight restrictions were imposed after the February 22 earthquake. Since then police have met accredited transport operators via the Canterbury Earthquake Recovery Authority, New Zealand Trucking Association and New Zealand Road Transport Association.

Police say the bridges will be monitored until they are repaired or replaced.