Passenger road service between the Tashkurgan and the Pakistani cities of Sost and Gilgit already exists and road service between Kashi and Gilgit (via Tashkurgan and Sust) started in summer 2006. However, the border crossing between China and Pakistan at Khunjerab Pass (the highest border in the world) is open only from May 1 to October 15 of every year. During winter, the roads are blocked by snow.