The 85-year-old New Zealand mountaineer says the road, now half-finished, will ruin the journey to the South Pole.
"I'm very strongly opposed to it," Hillary told the Wellington, N.Z.-based Dominion Post newspaper. "I think they ought to continue using their aircraft as they have done for years and years."
The purpose of the 1,000-mile road is to link McMurdo Station on the Antarctic coast to the Amundsen-Scott base, freeing up ski-equipped supply planes for other missions.
Hillary also criticized Great Britain for neglecting the historic huts used by early explorers of Antarctica. The huts are being threatened by advancing glaciers.