In its 1960 master highway plan, the Montreal Metropolitan Committee proposed a new long autoroute along the city's east-west street grid at the northern edge of downtown. The six-lane autoroute was forecast to handle as many as 4,500 vehicles per hour during weekday peak periods. Beginning at the Decarie Autoroute at Monkland Avenue in the Notre-Dame-de-Grâce section of the city (at the current EXIT 66 on Autoroute 15), the Mount Royal Autoroute was to extend in a northeasternly direction through Westmount underneath Mount Royal Park before emerging above ground at Rachel Street connecting to the unbuilt Autoroute 19 section of what is now Papineau Avenue. The only constructed section of this autoroute is the now demolished Pine-Parc Interchange at the intersection of Parc Avenue and Pine Avenue.