Construction on the Port Mann-Highway 1 Bridge project has reached the half-way mark.

The bridge will open with eight lanes in winter 2012/13.

The project is a key component of the provincial Gateway Program aimed at improving "the movement of people, goods and transit throughout the Lower Mainland," according to the province.

"From the iconic design of the new bridge, to the hours of traffic management to ensure that the highway remains open for use during construction, to keeping people informed about what's happening, work has proceeded safely, with minimal disruption," said Minister of Transportation and Infrastructure Blair Lekstrom.

"I also want to thank bridge users and highway neighbours for their patience and support. I urge everyone to continue to drive safely and watch for workers and slower moving construction vehicles. Safety is our highest priority as we move to complete the project as quickly as possible."

At a celebration to mark 50-per-cent completion of construction on Saturday, Premier Christy Clark acknowledged workers for their contributions to the project.

"Not only are these 1,500 workers helping to build our economy, they are helping to improve the lives of British Columbians," said Clark.

"Once complete, commuters will save an hour a day in travel time. That's one more hour a day that people can spend with their families instead of stuck in traffic."

Once all 10 lanes are complete, the 850-metre span cable-stay structure will be the widest in North America — as well as one of the longest.

Buses will run on the new bridge for the first time in over 20 years and there will be lanes for carpooling and cyclists.