625 ILCS 5/18c-6303

Any motor common carrier of passengers may add to, change, or reduce the level of its service to any point along a route over which the carrier is authorized to provide service, provided that the addition, change or reduction does not constitute discontinuance of service to any point along a route over which the carrier is authorized to serve, after the carrier has served notice in accordance with Commission regulations adopted pursuant to this Article, and without prior authorization.