Mild winter weather so far in N.W.T means the third season of work on the Inuvik to Tuktoyaktuk Highway likely won't begin until the new year, say contractors.

"It all depends on the weather and the ice right now," said Kurt Wainman, owner of Northwind Industries, one of two contractors on the project.

Although gravel hauls haven't started yet, Wainman said he has a crew of about 20 building an ice road to a gravel pit that's located about 14 kilometres from Inuvik along the portion of the highway that has already been constructed.

"We are preparing the ice to haul on. We've been flooding for two weeks and we'll be going for another two weeks," Wainman said.

When completed, the two-lane gravel highway will run 137 kilometres from Inuvik to Tuktoyaktuk. Construction is expected to cost $299 million.

About 150 people work on the project each year during the winter months.

The Tuktoyaktuk contractor, E. Gruben's Transportation Ltd., says its crews have also begun building ice roads to access its gravel pits on the northern end of the road.

Last year both contractors hauled enough gravel to fill more than 150 Olympic-sized swimming pools before the end of December. 

Building ice bridges strong enough to support the haul trucks depend on cold weather consistently below –20 C, or even better, –30 C, Wainman said. 

"To me the biggest challenge is climate change. It's just such a drastic change," said Merven Gruben, vice-president of E. Gruben's Transportation. 

Lack of snow, needed for building ice bridges and ramps, is also a problem for Tuktoyaktuk crews, said Gruben.

"Last year we started earlier, we were using snowmakers," Gruben said.

"That proved to cost us a lot of money and that didn't get us too far ahead. This year we are just going to wait it out."

Despite these challenges, both contractors say the highway will be completed on schedule by fall 2017/winter 2018.

Gruben said the highway will be completed, even if they have to "haul like hell."

The Department of Transportation has not responded to CBC's request for comment but it has said recently the project will be completed within the $299 million budget.