EDMONTON, Alberta – Canadian Pacific is once again drawing the attention of Canadian safety regulators over the derailment of four freight cars near Scotford, some 35.5 miles east of Edmonton, CBC News reports. The incident, which involved a train operated by remote control, occurred on the railroad's Scotford Subdivision on Dec. 8 and saw 26,000 gallons of liquid styrene leak from a ruptured tank car.

Canada's newly appointed Transport Minister Marc Garneau said, "I have deployed a Minister's Observer who will keep me informed while the Transportation Safety Board investigates a Dec. 8, 2015, derailment at Scotford Yard near Edmonton. Should the Transportation Safety Board's investigation uncover any concerns, I will not hesitate to take action in order to uphold safety."

Though more common on Canadian National, remote control is not new to Canada, having entered use in the late 1980s. However, there are no regulations restricting its use to yards or other non-main tracks. The Canadian Rail Operating Rules simply state, "Remote control locomotives in transfer service may only operate on the main track when a qualified operator is equipped with an operative operator controlled unit."

CN limits the speed of remote control trains to 15 mph.