No person shall cause or permit any railway train or railway cars or similar vehicle on rails to stop or stand or to be operated in such a manner as to prevent the use of any street for the purpose of travel for a period of time longer than ten minutes, except that this provision shall not apply to railway trains, cars or similar vehicles on rails while blocking or obstructing a crossing because of an accident which requires the operator of the train, car or similar vehicle on rails to stop at or near the scene of the accident. (Ord. 432 § 2(part), 1982).