The Exo Terrebonne-Mascouche and Exo L'Assomption sectors are the division responsible for providing public transit service to mainly the communities of Terrebonne, Mascouche, Repentigny and L'Assomption.
The Quebec Ministry of Transport produced a report in 1999 which analyzed the Lanaudière region's transport problems. This report overwhelmingly favoured a public transportation service managed within the region instead of the integration of existing public transit in L'Assomption and Les Moulins with either of the large Montreal (STM) or Laval (STL) systems. The result of this was the creation of the Conseil régional de transport Lanaudière in 2002, under the management of the six regional county municipalities of D'Autray, Joliette, L'Assomption, Matawinie, Montcalm and Les Moulins, with additional transit user representation on the board. This also required each MRC to manage operations in their territory, with a structure which may vary depending on different local needs.[2]
In June 2017, Quebec Ministry of Transport approved the law 76, which modified the transport gouvernance of transport entities in the Metropolitan Region of Montréal.[3]Exo then took over the operation of bus services for both Terrebonne-Mascouche and L'Assomption sectors.