Report it to the Council first - Wiltshire even give you a freefone number 0800 23 23 23 for all faults on the highways. Don't dial it from your mobile as it won't work, that is a different number that I cant recall at present but there are signs posted up around the County.
Report stuff/moan to your MP by all means and yes it makes the LA's jump when they get an MP letter - but just remember - while your letter of complaint is winging its way to him and he takes a few days to respond, time is passing out there on the road and any fault is still a hazard. Once a fault has been reported to the Council should anyone else have an accident and the Council haven't acted....
