Highway 417 is a controlled-access highway that traverses the lower Ottawa Valley and upper St. Lawrence Valley, bypassing the generally two-lane Highway 17 and providing a high-speed connection between Montreal and Ottawa via A-40. The freeway has also gradually been extended northwest from Ottawa alongside the old highway to its current terminus in Arnprior. Highway 417 currently has 42 interchanges from the Quebec border to Arnprior, with more planned as the highway is extended westward. Unlike other highways in Ontario and most of North America, exits are numbered from east to west. While a significant portion of Highway 417 is a rural four lane freeway divided by a grass median, the section within urban Ottawa is a busy commuter route as wide as eight lanes.