A reasonable and safe absolute maximum speed limit for all vehicles on all streets in the residential districts of the city, except those streets under the jurisdiction of the department of public works and buildings of the state; on the basis of a traffic investigation has been determined and is declared to be twenty five (25) miles per hour, as shown by appropriate signs which have been erected along the streets, and no vehicle shall be driven at a speed in excess of twenty five (25) miles per hour on any street in any residential district, other than a street which is under the jurisdiction of the department. (Ord. 2019-9-14, 9-9-2019)