Bidding for Existing Routes with an Increase of Hours. Whenever the total runs assigned to a particular route cause the total daily time to increase by more than thirty (30) minutes accumulative during the school year, the route(s) shall be posted at the Transportation Center by the Supervisor for a period of three (3) work days. All routes shall be filled on a classification seniority basis and subject to the bidding process in accordance with Section 20.4.