Toronto's new Light Rail Transit line has been hailed as a way to ease congestion in one of the city's busiest corridors. But it may make the problem worse before it gets better.

Coun. Joe Mihevc has warned that the construction of the Eglinton-Scarborough LRT station could snarl traffic at Eglinton Avenue and the Allen Expressway.

"This is a big project — a massive, multi-year project," he told CTVToronto.ca on Thursday. "We've got to be honest about that."

City officials may close parts of the south end of the Allen Expressway on occasion, effectively cutting the road off at Lawrence Avenue, said Mihevc.

Eglinton Avenue will also be trimmed down to one lane in both directions from Marlee Avenue to Glen Cedar Road, near the Upper Village shopping area.

The $8.2-billion project is expected to trigger a five-year long traffic headache for commuters. Construction is slated to last from 2013 to 2018.

"Eglinton and the Allen Expressway is already the most complicated and congested intersection that I'm aware of," said Mihevc. "That's why we've got to get a traffic management plan together."

Mayor Rob Ford was voted into office last year with a promise to squash the Transit City LRT project and swap in his own plan. The Eglinton-Scarborough project is moving ahead since provincial funding through Metrolinx was already in place.