Monday will mark the first post-holiday rush hour that will see typical traffic levels along with the regular toll on the Port Mann Bridge, and some drivers may experience major headaches 10 km away, on and around the toll-free Pattullo Bridge.

The Port Mann Bridge toll had been set at an introductory rate of $1.50 for cars, pickup trucks and small vans, but that rate doubled to $3 each crossing on Jan. 1. Rates for larger vehicles weren't discounted and remain the same, at $6 a trip for cars with trailers, and for cube vans and small motorhomes, and $9 for vehicles that are more than eight metres long.

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The base toll for a car trip across the Port Mann Bridge is now $3, up from the $1.50 introductory rate. (CBC)

Some discounts on the tolls are available, such as HOV lane discounts in rush hour and incentives to register for billing accounts but many see the biggest savings to the west, where trips across the older, smaller Pattullo Bridge are still free.

Residents in New Westminster, B.C., are concerned that a large number of south-of-the-Fraser commuters bound for Vancouver will alter their habitual routes in order to avoid the tolls.

New Westminster city councillor Chuck Puchmayr says he's expecting congestion on his city's streets to get much worse.

"I think tomorrow there will be a bit of a learning curve as people start to get their tolls and realizing that they've doubled, and they're going to start looking for alternatives, such as what people have already done," he told CBC News Sunday.

"They've looked at alternatives to the Port Mann Bridge and they're cutting through New Westminster to get to Vancouver, and vice versa."

Drivers also have a new route from the east to access the Pattullo Bridge, and other crossings further downriver, along the newly-opened South Fraser Perimeter Road.

But Puchmayr claims the SFPR has so far enabled more truckers to use the Pattullo to avoid the $9 dollar toll across the Port Mann Bridge.

The Transportation Investment Corporation, which runs the Port Mann Bridge tolling operation under the brand name TReO, says the South Fraser Perimeter Road is a designated alternate route.

"In accordance with the Provincial Tolling Policy, drivers of the new Port Mann Bridge must have access to at least one alternate route that is both convenient and free," TI Corp says on the Treo.ca website. "If you do not want to use the tolled crossing, you have the option to travel via the new South Fraser Perimeter Road."

with files from the CBC's Dan Burritt