B.C.'s Transportation Minister says the icy mayhem on the Port Mann Bridge on Thursday morning was not due to negligence or a design flaw, but because drivers failed to slow down and adjust to the conditions.

About 40 vehicles were damaged in chain reaction crashes when they lost control of their vehicles on black ice on the bridge.

Minister Mary Polak says the maintenance contractor Mainroad did everything it was expected to do to keep the bridge safe.

"They had been doing their patrols. They had been on the bridge a very short time before that and it was fine," said Polak today.

Instead Polak blames freezing temperatures, heavy fog and speed for the collisions during the morning commute, and says people need to slow down and drive according to the conditions.

"That's one of the challenges in the climate in which we live here in the Lower Mainland — weather can change quickly."

About 40 vehicles were damaged in chain reaction collisions on the new Port Mann Bridge on Thursday morning. (CBC)

Nevertheless, the contractor has been ordered to spray the bridge with de-icer more frequently and use salt as well if conditions require it.

The incident was the second since the bridge opened. Last month snow and freezing rain caused chunks of ice to fall from the bridges cables, damaging about 240 vehicles before police shut the bridge down.

The minister says in spite of the two mishaps the new Port Mann Bridge is a success.