Transport Minister Annette King is defending road user charge increases saying they are minimal and needed to maintain roads damaged by trucks.
Truck drivers, furious at new road user charges introduced by the Government this week, plan to clog city centres across the country tomorrow.
The nationwide protest, which organisers have promised will see 1000 trucks in the centre of Auckland, will disrupt commuters heading to work on Friday.
The trucks will be driven into the centre of cities between 7.30am and 9am in what trucking representatives say is the first national protest taken by the industry.
Ms King announced the increase in road user charges (RUC) on Monday, and they came into effect on Tuesday.
This angered truck companies who wanted notice so they could pre-purchase charge vouchers.
Ms King said today the increase was about fairness.
Car users paid for the roading system every time they bought petrol, those with diesel only paid through the charges and these had not risen to cover the costs created by trucks, Ms King said.
The increase means that for a small diesel car it will cost $3.28 more to drive 1000km, or $32.80 more for an average year's motoring of 10,000km.
For a larger vehicle, such as a three tonne SUV, it will cost an extra $49.20 per 10,000km.
A typical five tonne truck will pay an additional $53.80 per 10,000km, while a 23 tonne four-axle truck can expect to pay an additional $198.
Ms King said she had been advised to increase the charges by twice that amount.
The increases were minimal considering that large trucks did most damage on roads, responsible for a third of spending on road repairs.
"This is about fairness," Ms King said.
She acknowledged that there could be changes to the system in the future.
Ms King said she did not give notice this time because when she did in 2007 there was a $17.5 million mass pre-purchase to beat the deadline.
Road Transport Forum chief executive Tony Friedlander said the organisation's members were outraged.
The minister had previously promised a month's notice of any increases.
"I have never known members to be so angry over any issue," he said.
Ms King said she understood the protests were being organised before the increase in road user charges were announced.
Similar protests have been taking place around the world as the transport sector is squeezed by higher oil prices.
NZPA
Listen to RadioLIVE's Marcus Lush on Breakfast interviewing Tony Friedlander, CEO of the Road Transport Forum.