The Montreal to Trois-Rivieres route
Highway 40 east, 1 h 30 without traffic. Route 138 along the river is the scenic alternative: slower, much prettier, through villages like Maskinongé and Louiseville.
On arrival, the historic downtown and rue des Forges photograph well. The Grand Prix street circuit runs through those streets in August.
Return via Highway 40, or continue to Quebec City depending on the mileage you have left.