It shall be unlawful for any person, firm or corporation to cause or permit any railway train or railway car or similar vehicle on rails to operate or to be operated in such manner as to prevent use of any street for the purposes of travel for a period of time longer than five 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. 2275 § 1; April 19, 1966.)