The NZ Transport Agency says bridge crews are working hard at the Manawatu Gorge to establish a permanent route following the loss of the temporary road last week to flooding.
NZTA's Palmerston North State Highways Manager David McGonigal says the remainder of the slip material, which was being used as a working platform, washed away last weekend, meaning the bridges will need to be fully reconstructed before the road can open. The NZTA were initially hoping to get one lane of the bridges open for traffic, however, the accelerated programme of work means the fully complete bridges should be finished in around the same timeframe.
The NZTA is now aiming to fully reopen the road in late August or early September.
'The team are now working within the width of the existing road, which means we now need to build the bridges from either end rather than from the sides. To accomplish this, we've brought in one of New Zealand's biggest mobile cranes, which can lift 450 tonnes.'
Mr McGonigal says the lower structure of the bridges was effectively completed with the curing of the concrete now underway, and the next few weeks would see the bridge beams being laid and grouted into place.
Mr McGonigal says the NZTA understands the frustration of motorists, residents and businesses, and has assured them that crews are working as quickly as possible to restore access permanently.
'We were always conscious that the temporary road was just that - temporary - and although we would have loved Mother Nature to have spared it for a little longer, our bridge crews are working as quickly as they can to get the road open for good.'
Mr McGonigal says the NZTA has carried out a review of the safety and effectiveness of the temporary road while it was in place.
'While the temporary road was in operation, the economic benefits for the region, and the individual benefits for motorists, were quite profound and the feedback we received was that it made a real difference to people's lives.'
Mr McGonigal says that while the loss of the temporary road is disappointing, the NZTA's top concern was safety, and it had adopted a 'safety first' approach that had proved its worth.
He says the operation of the temporary road was conditional on a raft of safety measures including the 24/7 monitoring of the temporary road and its stability, the monitoring of river levels, the relocation of the road further inland at the earliest possible opportunity, and the closure of the road at the first sign of uncertainty.
'We needed to be absolutely sure the temporary road was as was safe as possible before we opened it. Our team identified potential risks early on and put in place robust safety systems to ensure they were fully addressed which included 24/7 onsite staff to monitor the road and river, and these measures proved to be effective, with the decision made to close the road to traffic well before the rising river levels could put motorists at risk.'
Mr McGonigal says crews are making strong progress onsite with the recent improved weather, and regular updates would be provided on progress until the road is reopened.
He reminded motorists to take care on the alternative routes, and to strictly observe speed restrictions at all times.