Times do indeed change.
No more guard's vans and the trusty old CZ weighed in around 250lbs wet as I recall.
Not that either of us has done any motorcycling in many many years.
And we wouldn't expect the railways to do any service they weren't doing every single day.
I wouldn't blame the TOC's entirely for the lack of "motorcycle conveyance".
Could you seriously imagine any TOC going to their insurers and asking for the conveyance of motor vehicles on passenger services to be included in the policy. They'd be laughed all the way out the front door (or at the very least have a couple of million quid added to their premium).
Whilst I believe that BR had its good points, that doesn't mean that everything they did was good (or even safe)
