Always keep to the legal speed limit for the road you are using. Speed limits for cars & vans when towing caravans or trailers.
30mph applies on all roads with street lighting unless signs show otherwise.
50mph applies on single carriageways unless signs show otherwise.
60mph applies on dual carriageways and motorways
It should be remembered that you must not travel in the right-hand lane of a motorway, with three lanes or more, if you are driving a vehicle drawing a trailer.