How are over-height vehicles safely removed from the motorway? Sometimes I see that the "over height load pull over" signs are positioned shortly before a low bridge, with no off-ramp for them to exit before the bridge. Imogen Swain, Auckland.

Approaching, for example, the Penrose overbridge, there are at least four places where height indicators set off an alarm, which activates the first warning sign. This allows the truck driver to take the nearest off-ramp and thus avoid the overbridge. As the truck gets closer to the overbridge, it is measured again and a second flashing light is triggered at the overbridge itself.

And, in similar vein:

I would like to know ...


• How many times the Penrose overbridge has been hit overall?

• When were the lasers installed?

• How many times has it been hit since the lasers were put in?

• Has anyone been seriously injured or killed?

• What is the estimated cost per accident when the bridge gets hit?

• What are the consequences to the driver who is at fault?

• Is any solution being planned?

• If not, why not?

• if there is, what is it and when will it be done?

Ange Boland, Auckland.

The graphic with this story shows the bridge-strike figures.

The lasers were installed in 1988. The Transport Agency cannot say how many times the overbridge has been hit since then as figures only go back to 2008.

There has been one fatality, in 1993.

The cost per accident is difficult to quantify as there are many different measures that could be used, and the Transport Agency acknowledges the greatest cost is the disruption to people's lives. In terms of the incident response itself the Transport Agency in Auckland has spent $203,000 dollars over the past seven years on incident response and material repair costs following bridge strikes across the network. The costs have varied from $1000 to $70,000 depending on the incident.

The Transport Agency has sought and recovered costs from the freight company involved, or their insurers, on each occasion. In the latest incident, on May 9, the driver of the vehicle carrying the digger which hit the overbridge has been charged with dangerous driving. This charge carries a maximum disqualification period from driving of 6 months. It is also punishable by a prison term of up to three months and a fine of up to $4500.

As far as solutions go, the Penrose Bridge is 4.57m high which is above the minimum legal height requirement for a highway bridge (4.25m). While the Transport Agency appreciates the frustration of those affected by the delays there are no plans to replace the bridge. There are other bridges of similar height on the network.

Transport Agency staff work with the freight industry to ensure its members are aware of the height requirements of this bridge and others on the network. The overheight detection warning systems are being upgraded to ensure an even more effective early warning to drivers of overheight vehicles.