Im sure you can go for this - local authotiries just anyone else have a Duty of Care to carry out works safely and not endanger or cause damage. Also this infringes Health and Safety regs as they have shown carelessness which has endagered your safety, particularly if the screen has been damaged. It was probably the case that the gritter was being driven too fast thereby scatering grit over a wider area, and causing to increase the velocity of the grit towards you if you were going in opposite direction, hence damage caused.

Search internet to look for a successfull claim and use it as your president.

I claimed for a new screen on my other car when gravel feel from a truck i was behind - the company didnt argue once i mentioned Duty of Care.

good luck