Thousands of Metro Vancouver drivers are bracing for a gas line replacement project that is expected to cause commuter chaos along one of the key routes through the region.

FortisBC will reduce Lougheed Highway to a single lane in each direction between Madison and Delta avenues in Burnaby.

Barricades and lane dividers were already in place Wednesday. Work to upgrade the natural gas line starts Thursday evening and things won't return to normal until sometime in mid-October.

Squeezing four lanes of traffic into two will likely lead to frustrating lines for drivers, especially during the morning and afternoon rush hours.

"Obviously, it is quite an inconvenience for drivers in that area, so the best thing to do is know your route before you commute and learn about some of those alternate East-West routes through that area," said Trevor Wales of FortisBC.

Those who rely on Lougheed, however, say the area is already busy and that the project will undoubtedly make things worse.

"It's bad enough at best of times with all the construction that goes on around here with the towers," said one man. "It kind of adds to it."

The work will also restrict some left turns and take away street parking, which has some small business worried their customers will go elsewhere.

"I believe that will probably really affect the sales of our fruit boxes for this month," said Leanne Ma, the owner of Edible Arrangement on Lougheed Highway near Willingdon Avenue. "But hopefully with our delivery service, people will choose to have it delivered instead."

In the meantime, work on the same project continues on 1st Avenue in East Vancouver, where business owners say they plan to seek compensation for the money those road closures have already started to cost them.

"We want to make sure, and I think FortisBC wants to make sure, that we keep track and keep on top of that as we move forward, so that any of the businesses that are hardest hit are looked after," said Nick Pogor of the Commercial Drive Business Society.

Fortis said it will work with businesses on a case-by-case basis and offer to help them with promotions and advertising if they are struggling, but stopped short of saying the company would write anyone a cheque.

With files from CTV Vancouver's Ben Miljure