Surface cracks close lane of SH2 bridge near Norsewood

Looking towards the temporary single-laning of the Mangatewainui Bridge south from Gundries Rd, between Norsewood and Dannevirke. Photo / Leanne Warr

A main highway bridge in southern Hawke's Bay is down to one lane after the discovery of cracking on the bridge deck.

But Waka Kotahi NZ Transport Agency assured this afternoon that the State Highway 2 Mangatewainui Bridge between Norsewood and Dannevirke is safe for traffic.

Stop/Go traffic management with a temporary speed limit of 30km/h is in place and contractors could be installing temporary traffic lights to control the flow of traffic later this week, pending repairs hopefully by the end of next week.

The repairs depend on what a statement said was "resource availability".

It said depending on weather and temperatures new seal would take at least 24 hours to set before both lanes would be open again.

The transport agency said people using the route should plan ahead for minor delays, comply with the temporary speed limit at the location and follow the directions of traffic management staff and signs.

Manawatū-Whanganui system manager Rob Service said the transport agency has a regular bridge maintenance and monitoring programme to ensure all state highway bridges remain safe and fit for purpose.

"As part of this, some cracking on the bridge deck was identified and repaired before Christmas last year and contractors have been monitoring the bridge since."

On Tuesday contractors identified a few areas in need of repair and the decision was made to close the lane to avoid further damage to the bridge before repairs could be made, Service said.

The transport agency says the route, which conects Hawke's Bay with Wairarapa, Manawatu and Wellington, has 6000-7000 vehicles per day, and is a key interregional link for freight to and from the Bay.

The bridge deck was resurfaced three years ago using a combination of fabric and chip seal. The fabric helps provide increased waterproofing to the concrete structure. The upcoming repairs will reinstate areas of surfacing that have deteriorated, supporting the ongoing maintenance of the bridge deck.