Bigger trucks have meant fewer vehicles on Napier roads, saving millions of dollars by reducing the number of trips made compared with normal-sized lorries.
In five years two Super B trucks have carted one million tonnes of wood pulp on the designated route between Pan Pac mill in Whirinaki and Napier Port,
The truck and trailers, designed and built by Rotorua's Kraft Engineering for Emmerson Transport (ETL), operate on High Productivity Motor Vehicle (HPMV) permits, which allow their 23.8m length and an additional 18-tonnes of weight above the 44-tonne standard weight limit.
Their New Zealand Transport Agency (NZTA) permits strictly limits them to the 18km route between the mill and the port.
"We've taken 3500 movements off the road per 12-month period," Emmerson managing director Ian Emmerson told Truck and Driver magazine.
"They're doing 28 to 30 total round trips a day, from 6am to 10pm, over two shifts."
Pan Pac's pulp division general manager Tony Clifford said that the Super-Bs saved more than one million litres of diesel for every year in operation. They were sanctioned by the NZTA as part of its highly-successful HPMV programme - aimed at improving the efficiency and productivity of NZ's national truck fleet. Thousands of trucks have now been approved to run at higher weights, subject to strict conditions, under the programme.
Pan Pac contributes more than $400m to the Hawke's Bay GDP, provides 1900 fulltime jobs and accounts for one-third of all products through Napier Port.
"The HPMV concept has been a critical part of delivering our product reliably and at the lowest costs, given the existing technology and the compliance regulations at the time," Mr Clifford said.
Road Transport Forum chief executive Ken Shirley said the HPMV programme was "a magical story of success".
"The beauty and the promise of HPMV was to recognise that all of the state highways and arterial routes can comfortably take up to 60 tonnes. Yes, the HPMVs are bigger, but they're better, safer, newer, fewer, with improved technology - so you're actually moving more goods with fewer, modern trucks."
NZTA's freight strategy manager Marinus La Rooij said there would be more HPMVs in the future for "very specific freight tasks, where the roads and the environment can safely accommodate them".
A review of trucks and trailers over 23m long is under way and should be finalised by the end of the year, he said.