AH42 or Asian Highway 42 is a route of the Asian Highway Network, running 2346 miles (3,754 km) from AH5 in Lanzhou, China to AH1 in Barhi, India.
It passes through the countries of China, Nepal, and India. It is the nearest Asian Highway to Mount Everest.
More than half of the route, from Lhasa to Lanzhou in China, is labelled as a "Potential Asian Highway."