When the tolls came off the Port Mann Bridge Sept. 1, 2017, traffic on the crossing increased overnight by a quarter.

Unsurprisingly, drivers who were accustomed to forking out the fee and cruising across the Fraser suddenly found their daily commute a lot less expensive but a lot more time consuming as additional volume snarled traffic, especially during rush hour.

Numbers provided by the Ministry of Transportation show that in 2018, the first full year of no tolls on the Port Mann, the average number of daily crossings increased 23 per cent, up from 132,000 per day in 2017 to 150,100.

"It's just something we are constantly dealing with, the volume of people who are travelling through the Lower Mainland," said Minister of Transportation Claire Trevena.

Trevena said removing the toll was the right thing to do.

"It was very unfair to have people living in one area paying tolls to get to work, to visit family and to do anything else," she said. "If you live south of the Fraser ... you should be travelling as freely as anyone else."

According to SFU City Program director Andy Yan, the Port Mann is suffering from the entirely predictable theory of "induced demand" which posits if you build it, cars will fill it.

"Induced demand is an idea from transportation planning which says when you start expanding these types of transportation systems — particularly centred around automobiles — they have a tendency to just create further demand," he said.

Yan believes the bridge is also a victim of poor transit options and the affordable housing crisis which is pushing people into the Fraser Valley and creating more commuters who need to get to jobs in Vancouver.

"What used to be a choice to move out to the burbs is quickly changing in metropolitan Vancouver to [a realization] that this is the only place where I can find a level of affordability," he said.

"What happens unfortunately is that this is, if you will, a phantom affordability because ... once you start factoring in the cumulative effects of long term commuting, affordability greatly diminishes."

Trevena says the NDP government has no plans to reintroduce tolls on the Port Mann.

"Our government does not believe that people should be paying tolls to fund infrastructure," she said.