I would always recommend reserving a cart if for no other reason just to stay out of the line at the bike barn waiting for one. They have also become much more strict about the check out and check in times of the carts. It used to be that you could rent a cart for 24 hours starting any time of the day but now the check out and in times for the carts are the same as the campground. They must be returned by 11 AM and they will not let you get one until 1 PM UNLESS you have a reservation at which point they will let you get a cart early. You must reserve carts at least one day prior to arrival.