We've come to accept that driving a car with hands-free phones is 'ok' unless you have an accident. In a car you need the hand more than when driving a train - for steering obviously, and in a typical urban driving scenario you're more likely to have other eejits in cars, pedestrians, etc etc, and more signs and traffic lights - several times a minute - although the stopping distances are shorter..
We've probably just accepted that if you can't beat it, you have to accommodate it as safe as you can, in a car. Is that going to be necessary for trains - bluetooth, limits on where/when/speeds etc etc.. - or blanket bans that aren't enforced if they can't be detected?
I feel as though it's been a bit different in road driving.
The legislation for using a phone while driving was originally created to address people using radios. That's why for a long time it was only actually an outright offence to hold a mobile phone while 'communicating', i.e. talking on the phone or sending an SMS, but not playing Candy Crush or scrolling the BBC News front page.
There's an entirely separate law prohibiting having "cinematographic equipment" in view of the driver, e.g. Netflix or YouTube, unless it's showing diagnostics about the vehicle, or imagery of the vehicle and its surroundings, like reverse parking cameras.
It was amended a few years ago to cover pretty much all mobile phone use while it's held in the hand, with exemptions carved out for paying at drive-thrus and emergency calls.
But the legislation has never really been
designed for mobile phones, merely adapted to account for them.
I'm not a train driver, so maybe someone will correct me on this, but I can't imagine train drivers were using CB radios and the like while driving, before mobile phones became popular. Assuming that's true, then the rules about using mobile phones while driving a train will have evolved in a much different way, which will have basically been a point in time where the industry said yeah, no mobile phone use while driving, except emergencies. Whether it's handheld or in a cradle or using voice commands, it's just not allowed.
Personally, I don't use my phone for calls etc at all while driving my car, hands-free or otherwise. I in fact worked for a railway consultancy which had an employee policy against using phones while driving for work purposes, even hands-free, and that was over a decade ago. I would potentially like to see road traffic legislation brought up to date to prohibit even hands-free phone calls and messaging. But I'm not sure we have necessarily deemed it as 'ok' - we've merely omitted to update legislation to account for modern technology. The government is just notorious for being behind the times when it comes to technology.