The City of Edmonton on Friday cancelled all speeding tickets issued on the basis of information gathered by intersection cameras such as this one. (CBC)The City of Edmonton is suspending use of some of its cameras used to catch speeders and cancelling some unpaid speeding tickets after it was determined the equipment was clocking drivers at speeds that were impossible to attain.

"They were very high to the point where you know it would have to be Superman going through the intersection," city transportation general manager Bob Boutilier said.

The problem was first noticed in July. Out of 245,000 speeding violations issued last year, 26 could not be verified. Most of these tickets were screened out as they are reviewed five times before they are mailed.

But one was accidentally mailed to an owner, which got the chief prosecutor's office involved.

"For us that was one ticket too many," Boutilier said.

Police were notified on Wednesday and Deputy Chief Daryl da Costa contacted the city. A decision was then made to cancel some tickets and suspend the program until the cameras are fixed.

The decision only affects tickets issued by "Speed on Green" or intersection safety cameras. Tickets issued by red-light cameras and photo radar are still valid and must be paid or dealt with in court.

Tickets that combine a speeding ticket with a red light violation are also being cancelled. The Crown prosecutor's office is determining what to do about those who have already paid their fines, da Costa said.

The cameras are under review to ensure the system is working properly.

"The major concern is that we felt we had filters in place to catch all of these things," da Costa said. "This needs to be a foolproof system for us."

Once the problems are resolved, all cameras will be recertified and the speed enforcement function reactivated, a news release said.