Since late June, Powell Street has been closed between Clark Drive and Hawks Avenue.
The road isn't expected to be re-opened until the summer of 2014 as construction crews shift the road south and build of an overpass over an existing railway.
"Drive-by traffic is greatly diminished and we've certainly seen an effect from that," said Brad Carpenter, whose company manufactures concrete fire pits on Powell Street.
He says while most of his business is from architects or other professionals, walk-ins are part of his business too.
"There's a lot less traffic on Powell Street. Everyone thinks it's closed in its entirety, which it's not," Carpenter said.
Mary Stuart, another local business owner, agrees.
"It has actually affected us a lot more than I thought it would," she said. "Eighty to 90 per cent is foot traffic walk-in sales, so it has not been good."
Stuart believes the City of Vancouver didn't provide enough information beforehand.
"They dropped off a pamphlet... and I saw it about two days before all the street signs went up and that was about a week or two before they started the process," she said.
No one from the city was available to comment, but the city's website says it has been consulting with businesses and residents for more than a year on the project.
The area's business improvement association says it's monitoring the situation.
The $50-million construction project on Powell Street will allow Port Metro Vancouver to create space to the north near the B.C. Sugar refinery building to add another east-west rail track on port land.
The project will also separate road users on Powell Street from the Burrard rail line route, which connects the port area on Burrard Inlet to the False Creek rail flats.