A CBC News investigation has revealed that thousands of Canadian trucking companies have been violating U.S. road safety rules by not keeping proper records and driving longer than is allowed.

Alberta-based companies accounted for 78 of those violations, records showed.

But according to Alberta officials, the vast majority of trucking companies operating in this province have good safety records, and collisions involving a tractor-trailer unit are relatively rare.

While U.S. figures revealed that thousands of Canadian trucking firms have violated regulations south of the border, Alberta officials say the industry's safety record is good. (CBC)Data from the U.S. Federal Motor Carrier Safety Administration showed that thousands of Canadian carriers violated key parts of the hours of service and logbook rules in 2009 and 2010.

Those numbers are evidence of a systemic problem within the Canadian trucking industry, said Winnipeg-based trucker Michael Arpin

Drivers are often pressured to be on the road for 26 hours straight — leaving them fatigued and accident prone, he said.

"I like to pass them very quickly, because I'm aware that they're tired," he said.

Collisions relatively rare: official

But according to Trent Bancarz, a spokesman for Alberta Transportation, truckers are still among the safest drivers on the roads.

In 2009 there were 44 fatal collisions involving tractor-trailers in Alberta, compared with 158 involving cars and 151 involving pick-up trucks or vans, according to provincial statistics.

"When you consider that tractor trailers make up about 15 per cent of all traffic on average, they're only involved in 1.5 per cent of all casualty collisions. Disproportionately they're not involved in very many at all," Bancarz said.

"A collision involving a tractor trailer unit is a relatively rare occurrence in Alberta."

Of the more than 24,000 trucking companies registered in Alberta, 142 had unsatisfactory provincial safety ratings last year, based on such things as mechanical inspections and proper log book entries, Bancarz said.

Ninety of those firms resolved the problems to the province's satisfaction. But 52 companies had their safety fitness certificates revoked, meaning they could no longer operate in Alberta, Bancarz said.