At its eastern terminus, Highway 409 crosses Kipling Avenue and merges onto Highway 401 express and collector lanes, while the westbound collector lanes diverge and become the westbound lanes of Highway 409.
At its eastern terminus, Highway 409 crosses Kipling Avenue and splits into two carriageways. The eastbound lanes cross Highway 401 on a flyover and become that highway's collector lanes, while the westbound collector lanes diverge and become the westbound lanes of Highway 409.