Driveways off Town roads are sited with Town approval.  If a culvert needs to be placed, proper sizing keeps the culvert small enough to allow the grader wing to not hook it while large enough to pass a 10 year storm event.  Please consult an engineer OR go to our links page to find the size of the drainage coming into the culvert, then input that information into the TR55 peak runoff calculator.  Your culvert retailer will be able to give you the correct size for the type of culvert (ie corrugated metal, corrugated plastic, smooth plastic, etc.)