Both the railway companies and the unions representing their employees agree the recorders would be helpful during Transportation Safety Board accident investigations.
But the union doesn't agree that the railway companies should be allowed to go a step further and use the devices to monitor daily activities of their locomotive engineers — something that is currently prohibited by the Canadian Transportation and Accident Investigation Act.
In the aviation and maritime industries, recording devices are wiped clean after trips where no incidents occur.
"Why is there a need to have different rules for the railway industry when they're covered by the same law?" said CAW national staff representative Brian Stevens.
"Locomotive engineers and conductors can be out on the road for 14 hours a day for many miles when they're scooting along the Prairies, so they're going to have wide-ranging conversations. Why does the employer need to eavesdrop in on that? There's no safety value in that."
But the Railway Association of Canada says monitoring the video and audio footage would give railway companies a better sense of whether employees are breaking safety rules, for instance by sending text messages while operating trains.
The companies could then use information to prevent accidents by beefing up their training efforts, association president and chief executive Michael Bourque said.
"These guys have a very important job to do, and it's critical that they're focused on what they're doing," Bourque said.
"I think people's privacy concerns have to play second to public safety."
Bourque also brushed off concerns that the railway companies would use the recordings to fire employees.
"That is ridiculous," Bourque said."The fact is that railways are facing a labour shortage. We're planning on hiring about 5,000 people a year for the next three years as people retire."
"And, because there's a renaissance in rail in Canada right now, we're growing; we need those people."
With a price tag of roughly $10,000 per locomotive for the recorders, the railway association estimates it will cost the two main carriers — Canadian Pacific Railway (TSX:CP) and Canadian National Railway (TSX:CNR) — a combined $22 million to $25 million to implement the new technology.
Bourque said railway companies might not be willing to pay that much unless the government gives them the green light to use the recorders as part of a broader accident prevention plan.
"They're not going to do it if they think a court order is going to stop them from using (the devices) after they've put them in," said Bourque.
"If your number one objective is safety, then you want this technology to prevent accidents, not to look at the accident after it's happened."
Transport Canada released a report last week urging railway companies to voluntarily install the devices, but stopped short of making them mandatory.
The issue was raised in the aftermath of a fatal train derailment in Burlington, Ont., last year. Transport Canada said because the train wasn't equipped with a recording device, it would never know why crew members missed the warning signal to slow down.
Via Rail has already begun testing recording devices in its locomotive cabs and said it is working with Teamsters Canada, the union representing its locomotive engineers, to establish a protocol for how the information gathered should be used.
Canadian Pacific and Canadian National are also having discussions with their unions regarding the issue.
"CP is supportive of the initiative but provided (the recorders) can be used for compliance monitoring," said spokesman Ed Greenberg.
"This is a complex issue and more discussions are required between the rail industry and the federal government."
But for the Canadian Auto Workers Union, ongoing compliance monitoring is "overly intrusive."
"We understand that from a public perspective, they want to make sure the rail is as safe as we contend it is," said Stevens.
"However, there are limits, and one of the limits in a Canadian society is that typically workplace conversations aren't subject to monitoring and recording by supervisors, no matter where you work."