The other favourite around my way is to take a dual carriage way and put cheverons half way through lane 1 to the kerb and half way through lane 2 to the central reservation. So you take a nice dual carriage way and turn it in to a single carriage way for no apparent reason.

Actually it is still a dual carriageway, and assuming there is no posted limit you can legally do 70mph (unless you are stuck behind a lorry and can't overtake, which is the real reason for these constrictions). :mad:

mb