The descriptions I hear regarding DCC suggest that it is operated in a manner more appropriate to road vehicles than to railways which require systems other than the loco driver's vigilance to keep the train from colliding with others and with incorrectly set turnouts etc. This is the difference between operating a model railway and operating a model train. Apparently Terry Flynn and I are the only modellers (here) actually operating model railways. (I never mentioned _racing_ slotcars)
I'm not saying very much at all about DCC - what I have said is that DCC is not the best option over analogue control in every instance.
(repeat from above) The descriptions I hear regarding DCC suggest that it is operated in a manner more appropriate to road vehicles than to railways which require systems other than the loco driver's vigilance to keep the train from colliding with others and with incorrectly set turnouts etc.
OK, I guess that makes three of us operating to proper railway rules! ;-)
I don't see any great difference: You assign your controller to a specific loco - I assign my controller to a specific block which contains my specific loco. From there on we operate in exactly the same manner. If you have two locos at the head of the train then you have to either call both or change both to an MU address - I still call up the specific block.
In my opinion those clearance cards are a form of "block" working in that they separate the trains to their own section of track. You don't run another train into that section so that you avoid collisions.
If you're operating a safety system that keeps trains separated by reasonable means other than operator/driver vision then you've moved beyond slotcars. Real trains aren't stopable within sight distance other than perhaps on the Nulabour Plains in Australia so railways generally don't rely on the driver to avoid collisions. Railways generally don't rely on the driver to set the routes either. If you are expecting/relying on the driver to avoid collisions and to set routes then you're playing slotcars, not operating a model railway.
Regards, Greg.P.