News release

TSB highlights risks associated with alcohol consumption before assuming safety-critical duties following 2021 head-on train collision in Prescott, Ontario

Gatineau, Quebec,  — 

Today, the Transportation Safety Board of Canada (TSB) is issuing a safety concern regarding alcohol consumption in Canadian rail operations following its investigation (R21H0114) into the collision and subsequent derailment of two Canadian National Railway (CN) freight trains.

On September 2, 2021, CN train 149 was travelling west to Toronto, Ontario (ON) on the north main track of the Kingston Subdivision, carrying 202 cars loaded with double-stack containers. Along the way, the train was to pass by a hand-operated switch that provides access to an industrial spur track in the town of Prescott, ON.

That same morning, CN train 532 was in the industrial spur and had received permission from the rail traffic controller (RTC) to reverse the switch to line the train onto the main track, despite train 149 being within the area limits. While approaching, the crew on train 149 realized that the switch was reversed and attempted to stop the train by activating the train’s emergency brake system. However, the train proceeded onto the spur where it collided head-on with train 532, causing substantial damage to both trains and destroying approximately 1000 feet of track. Two crew members sustained minor injuries, and one crew member received serious injuries.

The investigation determined that, at the time of the accident, the RTC had a complex workload, and his attention was diverted to other competing tasks. When he issued permission to train 532 to enter the main track, he assumed that train 149 had already passed the switch. Additionally, he did not obtain the required location report from train 149 before permitting train 532 to access the main track.

Under CN’s Policy to Prevent Workplace Alcohol and Drug Problems, the RTC submitted to a mandatory post-accident breath alcohol test; the results indicated that the RTC was either drinking alcohol at the beginning of his shift or had significant alcohol intake the early morning of or the night before work. The RTC’s performance and level of attention were likely affected by the persistent effects of alcohol consumption. Alcohol impairment involving employees in safety-critical positions can have significant adverse outcomes, affecting the safety of crews, passengers, and the environment.

In January 2022, the TSB issued a Rail Safety Advisory Letter to Transport Canada (TC) in which it indicated that they may wish to review the railways’ rail traffic control software safety prompts of all safety-critical tasks that can be overridden and confirm that there are adequate layers of defense to protect against RTCs overriding these prompts. In response, TC took immediate action to investigate the circumstances that led to this accident. CN issued a notice to RTCs in September 2021, prohibiting them, until further notice, from authorizing movements within area limits that have conflicts.

Safety concern

Currently, neither the Railway Safety Act nor its associated regulations prescribe a time period prohibiting the consumption of alcohol by railway employees before assuming duties. While CN’s Policy to Prevent Workplace Alcohol and Drug Problems states a zero tolerance for impairment at work, individuals are expected to self-assess and determine if the effects of alcohol have sufficiently diminished to be fit for duty.

In comparison, the Canadian Aviation Regulations stipulate specific time prohibition periods to allow for the elimination of alcohol, reducing the risk that a pilot, air traffic controller, or flight service specialist will assume safety-critical duties while under its influence.

Therefore, given that in Canada no time period prohibiting the consumption of alcohol by railway employees in safety-critical positions is required, the Board is concerned that such employees could perform their duties while under the influence of alcohol.

See the investigation page for more information.


The TSB is an independent agency that investigates air, marine, pipeline, and rail transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.

For more information, contact:
Transportation Safety Board of Canada
Media Relations
Telephone: 819-360-4376
Email: media@tsb.gc.ca