Question: How long is the highway Whitehorse/Cousins Airport was built to support as of 2012?
Sentence (from "Whitehorse/Cousins Airport"): Whitehorse/Cousins Airport (TC LID: CFP8) is an unpaved airstrip located in Whitehorse, Yukon, Canada, 8 NM northwest of the city centre between the Alaska Highway and the Yukon River.
Relevant evidence: Yes