A segment of the Trans-Canada Highway, the main part of Douglas Street runs approximately 5 km (3 mi) from Dallas Road on the Georgia Strait to just north of Saanich Road, where the Trans-Canada curves westward towards the Western Communities.
The intersection of Douglas Street and Dallas Road is the western end of the Trans Canada Highway, known as Mile 0.
The annual Victoria Day Parade also marches down the street by starting at Mayfair Shopping Centre and ending at the British Columbia Legislature.
Before the construction of the Patricia Bay Highway in the late 1950s, Douglas Street extended a further 2.7 km (1.7 mi) northward, ending at the current interchange of the Pat Bay Highway and Quadra Street.
Two disconnected segments of this former extension, which were not overbuilt by the new artery, retain the name Douglas Street.