OK - now been through the TRO.
The relevant articles are 36-39 (which set out how parking restrictions operate) and, to a lesser extent, 123-126 (which set out how virtual permits operate).
They basically state:
- you can't park for longer than the maximum period (article 36)
- but if you have a permit you can park for any period of time (article 39)
- unless you have a permit, you cannot park again in the same place (or within the same CPZ) for the "no return" period specified (articles 37 and 38).
So, not much to go on specifically in terms of how changing permit status interacts with the maximum period of staying. It seems the TRO wasn't drafted with your scenario in mind!
I still believe in this specific instance the grace period means you couldn't be served a PCN when you were as you were legally parked less than 10 minutes before it was served.
But for future use (and also relevant in this case) I wonder if you can construct a legal argument along the following lines:
- article 38 prevents "parking again" in a parking place within a controlled parking zone before the expiry of a specified period (one hour in your case)
- however, there is an explicit exemption to this restriction for permit holders.
- as such, you were permitted to commence a new period of parking in the same place/zone at any time up to the point your permit ceased at 12 noon.
- consequently, you are permitted to a new period of parking commencing from the point you switch off the permit, which allows you up to 2 hours of parking from this point in time.
Quite apart from this it doesn't seem logical for a 2 hour period to be inclusive of a period while you had a permit. It could lead to all sorts of anomalies or paradoxes, e.g.
- is a non permit holder who parks on Sunday allowed to be ticketed at 8.01am on Monday on the basis they have been parked over 2 hours and the restricted hours have commenced?
- would you still have been ticketed at 12.08pm if you hadn't switched your permit off on the basis you had been parked for over 2 hours without a permit at the start of the observation period?
- if you switched the permit on and off every 10 minutes, would you be eligible for a PCN as the grace period would never expire?
- the sign says "Resident permit holders or 2 hours". In the absence of an explicit statement to the contrary, "or" is normally interpreted to be inclusive, i.e. it is not required to satisfy one and only one of the conditions. A driver can expect to be allowed to rely on either or both. Consequently, a driver should expect to be able to park on the basis of being a permit holder, and also on the basis of the allowance for 2 hours where one is not a permit holder.