What causes school buses to get cancelled?

It seems like almost every winter the school buses close at least a few times, but what are the conditions that cause the buses to cancel?

According to Elk Island Public Schools (EIPS), although there are no conditions to warrant cancelling school, there are a few that can cancel the buses.

"We may suspend school bus service when there's a forecast or current temperature of -40 C including wind chill," says Laura McNabb with EIPS. "It could be regional or all bus service, it just depends on where that threshold is met."

"But we would never close the school."

McNabb said that the diesel that fuels the buses won't combust properly in temperatures below -40 C. 

"It's less to do with snowfall and more to do with temperature," McNabb said.

Other conditions such as icy roads or heavy snow may cause delays with the busses, but it rarely leads to a cancellation.

Even if buses are cancelled, EIPS allows parents/guardians to decide whether or not to send their child to the school.

"Some parents would choose to keep their children at home if the busses weren't running, while others choose to bring their children to school [themselves]."