There is a grey area here Howard...
According to the BBC digital ceefax on the TV ...I quote
" £10 per day to use UK roads"
So UK roads by the look of it....not just motorways.
I cant see myself how they could make it work on motorways only...not without mammoth investment in Toll Booths etc right across the network. The admin costs, the build costs, would almost defeat the purpose of having it in the first place.
You are right about the Ferry companies Martin, they wouldnt be keen...but would they have a choice?