The incident happened around 7:30 p.m. Friday near Saint-Roch-des-Aulnaies, about an 130 kilometres east of Quebec City, on the south shore of the Saint Lawrence River.
Jean-Marc Lachance with Environment Quebec said that the truck spilled between 20,000 and 30,000 litres of fuel.
He said the contaminated snow will be pumped into a vacuum truck and any contaminated soil will be scooped up using an excavator.
The lanes will remain closed as emergency workers try to recover as much of the diesel as possible.
They also have to remove the truck without causing any more spillage.
Environment officials said there are no rivers or streams near the spill.