N.J. Stat. Ann. § 5:3-56

2. A rider shall not board or attempt to board any amusement ride if he is knowingly under the influence of any alcoholic beverage as defined in R.S.33:1-1 or under the influence of any prescription, legend drug or controlled dangerous substance as this term is defined in P.L.1970, c.226 (C.24:21-1 et al.), or any other substance which affects the rider's ability to safely use the ride and abide by the posted and stated instructions. The operator of the amusement ride may prevent a rider who is perceptibly or apparently under the influence of drugs or alcohol from riding on an amusement ride. An operator who prevents a rider from boarding a ride in accordance with this section shall not be criminally or civilly liable in any manner or to any extent whatsoever if the operator has a reasonable basis for believing that the rider is under the influence of drugs or alcohol.