It would be worthwhile speaking with an attorney; you may have a  claim or cause of action. The town could be liable if 1) their negligence or carelessness caused the accident; and 2) the town either  had actual notice of the condition or problem, or reasonably and practically should have  known of it. Since the town's work crew presumably left the gravel behind without leaving warning signs, it may be that the crew (and therefore the town) both caused the condition and would be considered to have notice of it.Suing a municapility can be tricky--not only must the town's knowledge of the condition be shown, but there is a shorter time line to bring the claim and certain procedural requirements to comply with. Therefore, you should speak with an attorney right away, if you would like to pursue a claim if possible, and not delay--delay could cost you an otherwise valid claim.