Highway 550 (Ontario)

Infobox road
highway_name = Highway 550
marker_

alternate_name = Second Line


length_km = 26
direction = East/West
starting_terminus = Gros Cap, Ontario
ending_terminus =
junction =
established = 1955?
cities = Sault Sainte Marie, Ontario
aadt =
commons = category

Highway 550 is a secondary highway that runs east/west from the city of Sault Ste. Marie, Ontario to the hamlet of Gros Cap. It is known as Second Line within the Sault's city limits.

Its eastern terminus is an intersection with Highway 17, the Trans-Canada Highway, at the north end of the city. From here it is a four-lane undivided road, used heavily by commercial truck traffic which now use Carmen's Way, the truck bypass linking Second Line with the International Bridge. Trucks are now able to avoid the downtown core by using Hwy.17, Hwy 550, and Carmen's Way to reach the border with the U.S.. Hwy 550 reduces to two lanes west of Goulais Avenue. The highway intersects with Highway 565, also known as Airport Rd., which ends at the Sault Ste. Marie city limits, at Base Line Rd. Highway 550 continues to its western terminus, at a roundabout at the shore of Lake Superior, in Gros Cap.