Many times when there is a traffic incident resulting in a sign, post, barrier, mailbox, or anything else struck, that the police want to charge the driver with "Striking Fixtures." This is pursuant to S.C. Code § 56-5-1250. The problem with this is that there is absolutely no law in South Carolina against being the driver of an automobile that hits any object on the side of the road.
Here is the full text of the statute:
SECTION 56-5-1250. Duties of driver striking fixtures upon or adjacent to highway.
The driver of any vehicle involved in an accident resulting only in damage to fixtures legally upon or adjacent to a highway shall take reasonable steps to locate and notify the owner or person in charge of such property of such fact and of his name and address and of the registration number of the vehicle he is driving and shall upon request and if available exhibit his driver's license and shall make report of such accident when and as required in Section 56-5-1270.
This law does not say you can't hit something on the side of the road. It just says if you do, you must take reasonable steps to notify the owner.
The law mandates that a driver who hits something on the side of the road, and damages it, must take reasonable steps to locate and notify the owner or person in charge. The law does not require anyone to call 911 or contact law enforcement. The law further references S.C. Code § 56-5-1270, which describes what to do when law enforcement wasn't contacted. There is no requirement to do anything immediately as there is with the "hit and run" statute dealing with a personal injury.
What is reasonable is going to be a case by case basis. If a motorist accidently knocks over a pole in a business parking lot, and the business is open, it is probably reasonable to expect them to go inside at the time to tell and employee. If a motorist knocks over a fence post outside of a house in the middle of the night in a strange neighborhood, it might not be reasonable to expect them to knock and wake up a stranger, but instead to maybe leave a note (if they have paper and a pen), or to instead mail a letter the next day to the home's address with his name, address, and registration number of the car.
The one time where it is likely that the law creates an obligation to immediately notify law enforcement is a situation where a motorist knocks over or severely damages a sign or device important for safety. For example, if you knock over a stop sign you should likely try to prop it back up (if possible), and then call the police so they can direct traffic until a maintenance crew can be dispatched. But if you do so you would not have violated any "striking fixtures" law, and unless there is evidence that you are guilty of some other crime (too fast for conditions, DUI for example), you shouldn't be criminally charged. (HINT: if the police ask how your car ran off the road just say you wish to remain silent. Unless they saw it happen they have likely won't have any evidence to present against you in the event they try to write you a ticket).
There are special rules for situations where the damage is over $1,000, and that requires a report be filed with the DMV even if the police weren't involved. You should also keep in mind that you likely have an obligation under your car insurance policy to report all situations in which a claim is going to be made.
As with any other situation involving the police, if you are questioned after the fact about a traffic accident and are accused of "leaving the scene" or "striking fixtures" it is advisable to notify the police that you are not making any statements or answering any questions until you speak to an attorney. You do not have to allow them to search your car, or to enter your garage to inspect your car unless they have a warrant. You are under no obligation to ever admit anything to police, including whether or not you were the driver of a vehicle involved in an incident or whether or not you had been drinking.