He backed calls from West Coast Regional Council chairman Ross Scarlett to put the realignment back on the agenda.
Mr Scarlett said he would be submitting to the Canterbury draft regional transport programme to have it fast-tracked.
Greymouth-based Aratuna Freighters has 20 trucks plying the Arthur's Pass highway between the West Coast and Canterbury daily, and Mr Havill said that section of road was not up to State highway standards.
"Two trucks can't even pass safely - it is far too narrow. We've just been lucky so far."
Trucks negotiating the narrow carriageway had to cross the centreline to manoeuvre around corners safely.
"The truckies all know the dangers of the road, but I'm more worried about tourists who do not know the road, and motorists who speed.
"Vans have gone down the bank there.
"It's a nasty piece of road and I support Ross Scarlett in getting it improved," Mr Havill said.
It was even more "dodgy" in the winter, especially in the shaded areas where the road iced over.
NZTA regional director southern Jim Harland said today he understood the concerns.
"We are close to completing design work to improve its safety and we believe the priority the project has been given in the 2012-13 State highway plan is appropriate in terms of cost and how it contributes to the priorities in the government policy statement (GPS) on land transport funding."
He said the GPS required NZTA to take into account both national and regional transport priorities within the available funding in the 2012-15 national land transport programme, to be launched at the end of August.
He said the 2013-15 Canterbury regional transport plan did not identify the project for funding,
"The draft plan states it is likely to be recommended for inclusion in the 2015-18 programme."
Mr Harland said crash data showed there had been no fatal or serious crashes on the worrying section of the highway between 2002 and last year.