Sorry to sound sceptical, but in what way has the accident cost you money? If the council was negligent and you were hurt then you deserve a fulsome apology. But I don't see how taking cash from the council's already depleted coffers and giving it you will change anything for the better.
Should have said that the council should have a procedure for complaints on its website. Or you could ask your councillor to press for the road sign to be moved to a more suitable position (assuming the sign belongs to the local authority and not the department of transport).
I agree with asmallbunch. I think a call to thew council to make them aware should suffice. If they send you a small bunch of flowers <not the Mnetter> then that would be a nice touch, but I personally wouldn't be demanding money.