Although on the whole, the STM metro is a safe place, some terrible accidents have happened in the past which could have been easily avoided with the proper safeguards.
In addition to honest accidents, in the past, people have used the metro in suicide attempts.
In preparing for the expansion of the blue line, the STM is looking to prevent more accidents from happening; as the orange line is expected to be more crowded than usual. More people equals more possibility for accidents of this nature.
With that said, the STM will be conducting a feasibility study at 13 stations on the orange line. The biggest obstacle faced by the STM at the moment is cost.
According to a source the estimated cost is between 10 million and 15 million per station. Ouch!
The transit system in Toronto faced a similar issue regarding the cost of installing barriers. Basically, the entire project was scrapped due to financial reasons.
The STM has a lot of issues to deal with at the moment, like slow card terminals, chronically late buses, and cleanliness. Should the bulk of their financial resources be spent on installing these safety barriers? Only time will be able to answer this type of question.