Quake reminder of need for viaduct work

Photo / Brett Phibbs.

Christchurch's huge earthquake today is a timely reminder why Auckland's Newmarket Viaduct is being replaced, says the New Zealand Transport Agency (NZTA).

The southbound lanes of the viaduct are being closed for up to 36 hours this weekend from 5pm today to allow the a new motorway overbridge which has been under construction to open and for traffic to be switched from the old bridge to the new.

The closure is expected to cause widespread traffic problems - about 60,000 vehicles use the viaduct on an average Sunday - and Auckland motorists have been advised to stay off the road if possible.

Aside from improving traffic flows and capacity, one of the key reasons the viaduct was being replaced was its ability to cope in a major earthquake.

NZTA spokesman Andy Knackstedt said the Christchurch earthquake was a "timely reminder" of why the viaduct project was going ahead.

"One of the main reasons to do the work is to strengthen the viaduct to have strength to withstand a large earthquake as well as to cope with the increasing volumes and weights of trucks," NZTA spokesman Andy Knackstedt said.

While the old viaduct was built to withstand at most a one in 500-year earthquake, the new viaduct should withstand a one in 2500 to 5000 year quake.

"The viaduct closure is going to impact a huge number of people on Sunday, but imagine what the potential would be if it were closed for months if there were to be significant damage," Mr Knackstedt said.

Mr Knackstedt said NZTA surveys showed 87 per cent of Aucklanders knew about the viaduct closure and he hoped most would heed the message and stay away from the roads.

Trains throughout Auckland will be free of charge as authorities try to encourage those who do want to travel to stay out of their cars.

Emergency services will get regular updates on traffic congestion this weekend as the viaduct, the busiest stretch of motorway in the country, closes.

The Fire Service said it did not expect too many problems because motorists tended to get out of the way in a hurry when a heavy fire truck laden with water and with its red lights flashing wanted to get through.

It had also made plans to use fire trucks at either end of the closure rather than try to get through traffic.

However, St John Ambulance paramedics have added to their existing fleet of two emergency motorcycles with a new Honda Police Special, specially designed with extra wiring to take electrical gear used by emergency services.

When completed in 2013 the new viaduct will have four southbound lanes and three northbound lanes.

- NZPA