John Chisholm got a bill for crossing the Port Mann Bridge – even though he was was on Salt Spring Island.

Joe Desroches got a bill for a red Toyota crossing the bridge – even though he only drives a Chevy.

These are just some of the people who have told CTV News they’ve received unpleasant surprises in the mail demanding payment for crossings of the Port Mann Bridge they could not have made.

And figures given to CTV News by the Transportation Investment Corporation, the company that operates the bridge, show the numbers of bogus bills sent out could be higher than expected – at some 150 people a month.

“I was upset. Why should I pay for someone else’s car crossing the bridge?” asked Desroches, who was billed for two crossings in June that amounted to about $6.30.

He added he felt pressured to pay for fear that ICBC would refuse to renew his license.

“It’s not right. It’s not fair,” he said.

TI Corp refunded both Desroches and Chisholm their money, but only after the drivers called to complain.

The company said cases such as these are “rare” and that it only receives one complaint for every 20,000 crossings.

“The system is accurate. And like any organization that handles the volume of transactions that we do, there are going to be errors from time to time,” said spokesman Greg Johnson.

But with an average of 750,000 people using the bridge each week, that works out to some 150 confirmed complaints a month.

And that doesn’t include drivers who might not even notice the extra bill and pay anyway.

“People are going to be paying for something they’re not using,“ Dennis Legault told CTV News in 2013, after his pickup truck was dinged $1.50 for crossing the Port Mann Bridge even though he lived in Kamloops.

In 2013, Surrey resident Dave Stewart was billed because his license plate matched what was recorded by the bridge’s cameras – but the car that crossed the bridge had Washington State plates.

“This is just absurd,” he told CTV News at the time.

John Chisholm told CTV News it was “impossible” for him to have crossed the bridge and owe $11.75 because he was nowhere near it. His ferry reservations show the vehicle was on Salt Spring Island at the time.

“They tell me wacko stories. Tell me honestly how you got my plate on that bill when I’m not on that bridge,” he said.

What’s behind many of these mistakes is the bridge’s payment system. When a car has a decal designed for payment, and crosses the bridge, it’s usually very accurate, Johnson said.

But for cars that do not have a decal, the bridge’s toll system works by taking pictures of the front and back licence plates. In a perfect world, a computer uses optical character recognition to read the plate, checks with ICBC’s database of drivers, and sends the correct driver the bill.

But in a case where the photo is blurry, the system can fail by misreading the plate. When that happens, the misread plate number’s owner is wrongfully sent the bill out of the blue.

When the drivers complain, they’re refunded quickly, said Johnson. But he said he didn’t know how much money has been returned to date. And he said he didn’t know how many bills were sent out in error.

One solution might be to make sure that the plate that’s read matches the make and model of the vehicle photographed crossing the bridge. But Johnson said the company doesn’t have the capability to do that.

Desroches’s wife, Kathy, told CTV News she has a simpler solution: “Take the tolls off the bridge. That’s the ideal situation.”

B.C.’s new NDP government ran on that platform. A statement sent by the staff of Minister of Transportation Clare Trevena says the government will have a plan to dismantle the tolls ready by the end of the summer.