At the Ontario-Quebec border in L'Isle-aux-Allumettes Route 148 continues into Ontario as Highway 148.

Route 148 then continues west on des Allumettières Boulevard towards Aylmer.

The section of Route 148 between Lachute and Buckingham was the only major route on the north shore of the Ottawa River between communities in the eastern Outaouais region and Gatineau and Montreal.

Construction of Autoroute 50 to the north of Route 148 was completed on November 26, 2012, and now provides a faster and safer route between communities in the eastern Outaouais region and Gatineau and Mirabel.

For many years Route 148 included a section of Rue Principale west of A-13 and most of Boulevard Saint-Martin in Laval until it was decommissioned in 2012.