The B.C. Ministry of Environment gave an environmental green light to a major expansion of the Port Mann Bridge and an adjoining highway between the Vancouver suburbs of Coquitlam and Surrey on Thursday.

An Environmental Approval Certificate was given to the Ministry of Transportation for its Gateway Project, which includes another bridge adjacent to the Port Mann Bridge and widening of Highway 1, as well as upgrading interchanges between McGill Street in Vancouver and 216th Street in Langley.

Proponents of the $1.5 billion project say it will reduce congestion, ease traffic demand and allow buses on the Port Mann Bridge for the first time in two decades.

The project is still subject to federal and provincial permits and authorizations, but construction could begin as early as the fall of this year, and is expected to be completed by 2013.

The environmental assessment includes conditions for the construction of the project, including consideration for air quality control, fisheries and surrounding habitats, water quality and noise management.