Eight lanes of the new Port Mann Bridge will open Saturday after a four-year, $3.3-billion construction project.

Crossing the Port Mann Bridge, which connects Coquitlam to Surrey, has been a commuter's nightmare since construction began. For the last three months, drivers have been sharing three eastbound lanes.

The Ministry of Transportation and Infrastructure said eight lanes of the 10-lane bridge will open Saturday. When the final two lanes open in 2013, the bridge will enter the Guinness Book of World Records as the widest bridge in the world.

Officials predict the new lanes will cut travel time by about 30 per cent, but it will come at a cost.

The first week will be free, but beginning Dec. 8 cars will be tolled $1.50 each way.

The tolls will jump to $3 on March 1, but the government says drivers who register for an online tolling account by Feb. 28 will continue to pay the introductory rate for another nine months.

Cars pulling trailers or light trucks will pay an introductory rate of $4.50, which will jump up to $6 on March 1 for non-account holders. The introductory rate for motorcycles will be $1, a reduction of 50 cents off of the regular toll.

Semis and tractor-trailers will be paying $9 per crossing.

TransLink users will also be able to enjoy shorter commute times with the launch of the first rapid bus service over the bridge in nearly a decade.

Beginning Monday, the new express bus will travel from Langley to New Westminster in 22 minutes.

The bus will run every 10 minutes during the morning and afternoon rush hours, and every 30 minutes during non-peak times.