Traffic on the new Port Mann Bridge has been declining since tolling took effect last year, but officials are offering a new incentive to anyone who still wants to sign up for its electronic billing system.

Despite being bigger and faster than the old bridge, the new Port Mann is less popular; CTV News has learned traffic was down nine per cent in December 2012 compared to the previous year, and crossings have dropped an average of six per cent every month for the last three months.

Meanwhile, traffic was up on the Alex Fraser Bridge in December, and there was a 25 per cent increase in traffic on the Patullo Bridge in January.

Transportation Investment Corp., which manages the Port Mann Bridge, insists the decline in drivers was anticipated.

“It’s not surprising at all that drivers are going to try out the tolled route and try out the un-tolled route,” spokesman Max Logan said.

Still, drivers who have yet to sign up for TReO’s electronic tolling system are being given a new incentive to join.

Anyone who registers by June will be given two free crossings per vehicle, and a credit for any license plate processing fees incurred over the previous 30 days.

Unregistered drivers are hit with a $2.30 fee that officials say covers the cost of confirming their home address and mailing a physical bill.

Registered drivers are given a windshield decal to detect usage and billed automatically.

The provincial government said it’s not worried the declining traffic means it won’t recoup some of its investment in the $3.3 billion Port Mann/Highway 1 Improvement Project.

“There isn’t a likelihood that the revenues won’t be achieved,” said Transportation Minister Mary Polack.

Transportation Investment Corp. said if the numbers don’t pick up by the end of the year, they will evaluate rates and consider new discounts for 2014.

Logan said once all highway upgrades are complete, Langley drivers are expected to save an hour on their roundtrip by using the Port Mann, making a toll detour less attractive.

With a report from CTV British Columbia’s Mi-Jung Lee