Highway 99 is a provincial highway in British Columbia that runs 377 kilometres (234 mi) from the U.S. border to near Cache Creek, serving Greater Vancouver and the Squamish–Lillooet corridor. It is a major north–south artery within Vancouver and connects the city to several suburbs as well as the U.S. border, where it continues south as Interstate 5. The central section of the route, also known as the Sea to Sky Highway, serves the communities of Squamish, Whistler, and Pemberton. Highway 99 continues through Lillooet and ends at a junction with Highway 97 near Cache Creek.

Interstate 5 (I-5) is the main north–south Interstate Highway on the West Coast of the United States, running largely parallel to the Pacific Coast of the contiguous U.S. from Mexico to Canada. It travels through the states of California, Oregon, and Washington, serving several large cities on the West Coast, including San Diego, Los Angeles, Sacramento, Portland, and Seattle. It is the only continuous Interstate highway to touch both the Mexican and Canadian borders. Upon crossing the Mexican border at its southern terminus, the highway continues to Tijuana, Baja California, as Mexican Federal Highway 1 (Fed. 1). Upon crossing the Canadian border at its northern terminus, it continues to Vancouver as British Columbia Highway 99 (BC 99).