(02 Jun 2019, 10:15 am)streetdeckfan wrote I'm surprised that loophole hasn't been closed
There's national examples, but arriva demonstrated in the past you can have different route numbers and maintain a service.
The only real way to close the loophole is to set restrictions on through-services so that everybody would have to get off and back on to continue. But that just seems a waste of time.
I wouldn't imagine local authorities want to clamp down on it either, they provide useful connections to further places.