RickM,

(One passage only). That said, much of the UK plan remains restricted. I assume (but cannot know) that they have criteria defined in terms of who is/is not an Essential User.
I am reasonably sure the UK has defined 'essential user' and the fuel emergency plans had an "outing" in 2000 when a sudden protest by farmers initially, joined by hauliers quite literally nearly stopped the UK. Here is one link:http://news.bbc.co.uk/1/hi/uk/924574.stm

The UK plans were then explained to a limited audience, mainly within the fuel supply industry, as supplies dwindled and we edged towards declaring a State of Emergency. The most visible sign was the designation of a few petrol stations as only for 'essential users' and steps to ensure emergency serives, hospitals etc had supplies.

I would expect far more is in the public domain, but have not delved further.