Hi Michael
Have a look at the home page of this website where there is a section on towing law
http://www.practicalcaravan.com/legal/index.html
The part which deals with on street parking says:
'Do not park your caravan:
where it may cause an obstruction
at night on a road without lights
in street parking bays as some local laws forbid this
at a parking meter, as caravans are not permitted
unless securely braked or chocked to prevent movement '