Commuters coming into downtown Vancouver from the east could be in for a headache today, the first day of a year-long closure of a major traffic corridor.

Powell Street is being closed between Clark Drive and Hawks Avenue in order to shift the road south and for the construction of an overpass over an existing railway right-of-way.

The $50-million project 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.

The Powell Street Overpass project is expected to be completed some time in the summer of 2014.

Jerry Dobrovolny, director of transportation for Vancouver, said drivers who normally use the route will have to make other plans in the meantime.

"There's about 30,000 cars a day that use that corridor," he said. "For people coming off the freeway, you know, choose other routes: 1st Avenue, Broadway, 12th Avenue — different routes into the downtown."

Dobrovolny says the city will be monitoring traffic flows in the area and looking for congestion points that need to be addressed.

Buses re-routed

TransLink began preparing for the closure in mid-April, when it added diesel buses to two routes that had been serviced by electric-powered buses that followed the path of overhead trolley lines along Powell. Those routes, and others that have been using Powell Street, will be using Hastings Street as a detour around the construction zone.

Exact detour details and bus stop changes are posted on the TransLink website.

A few buildings were demolished to make way for the road shift at the narrowest portion of the roadway, around Raymur Avenue.

The city says remaining businesses along the closed part of Powell Street will remain open during construction, with access via side streets and alleyways.