John Baxter and his two daughters were killed at this railway crossing in west Edmonton on May 4. (CBC)CN is updating the mechanism that controls traffic at an Edmonton railway crossing where a man and his two young daughters died after their truck was hit by a Via passenger train two weeks ago.

The old system used to trigger the warning system at the crossing when a train crossed a certain point on the track. The new system, known as Constant Warning Time, takes the speed of the train into account, said CN spokeswoman Kellie Svendsen.

"The older system that was in place activated based on a maximum train speed on the line," she said. "That was 70 miles per hour ... what Constant Warning Time does is it understands the speed of the train. And then the gates go down based on speed not based on the location of the circuit."

On May 4, John Baxter and his daughters, Julianne Rose, nine, and Coral Sky, seven, were killed when the Via train struck their truck during a spring snowstorm at the crossing near the intersection of Winterburn Road and 111th Avenue in west Edmonton.

In the days after the crash, people in the area said the warning lights and crossing arms didn't always work at the crossing — meaning the arms would go down even if there was no train.

Svendsen said the arms have worked properly, but because freight trains are slower than passenger trains, the gates would sometimes stop motorists for more than a minute.

CN plans to install and test the new equipment at the crossing this week.