A sign of the over-use of the main network in Île-de-France is also the consistently heavy traffic: the hourly flow often stays at maximum level from 6 am to 9 pm, with daily throughput virtually stable throughout the year.
Ce système a évolué au fil du temps et au gré des modalités d'organisation du transport collectif régulier par route en Île-de-France, ce qui a conduit la Commission à distinguer deux périodes: