Commercial vehicles travelling on the 407 Express Toll Route have been hit with thousands of dollars in overbilling and duplicate billing, CTV News has learned.

The all-electronic toll highway, which stretches from Burlington to Pickering, has been driving up an accounting nightmare for some trucking and trailer companies.

According to documents obtained by CTV, commercial vehicles travelling on Highway 407 have been tolled twice for the same trip.

The 407 ETR insists the issues are very rare, but invoices show tens of thousands of dollars in improper billing.

Wilkins Tri Axle, a trucking company based out of Brantford, Ont., was repeatedly charged twice for single trips. One invoice over a one-month period in 2007 shows 19 overlapping charges. In total, the company found more than $47,000 in errors over eight years.

The reason: the 407 charges all vehicles that enter onto the highway, either by reading the vehicle’s registered transponder or by reading the vehicle’s rear license plate.

But with tractor-trailers, the 407 sometimes bills the transponder on the truck’s windshield, and it also charges the license plate of the trailer that the truck is pulling – even though a singular trip.

Michael Daviau, owner of Load King Trailer Rentals, says the ETR is basically charging his trailers for the trucks’ trips.

“Obviously, people are finding it very frustrating, dealing with the 407,” Daviau said, adding he has to spend time on the phone waiting for customer service representatives to resolve the matter.

Daviau said he has resisted paying the bills and, as a result, was been slapped with a notice that the government will not be renewing his company’s licence plates.

The Ontario government effectively washed its hands of the 407 with its sale back in 1999. However, if there are outstanding toll charges, the Ministry of Transportation can legally deny plate renewal.

In most cases brought forward to CTV News, disputes have been eventually resolved.

In the case of Wilkins Tri Axle, the ETR agreed to pay back $54,000. But it’s up to the companies to find the errors.

In at least one case, a dispute resolution came with a promise to keep quiet.

In one non-disclosure agreement, the 407 agreed to pay back more than $100,000, as long as the company agreed to “not disclose its existence or contents thereof to any third party, unless required by law or first consented by the other party.”

ETR spokesperson Kevin Sack said overbilling only happens in rare cases.

“The likelihood is very, very small, but it can happen,” Sack said.

The spokesperson maintains that there is no problem with the ETR’s billing or detection system. But anyone with issues is urged to contact the 407 as soon as possible.

With a report by CTV Toronto’s Ashley Rowe