Khunjerab Pass (sometimes called Khunerjab Pass) is a high mountain pass on the northern border of Pakistan with China, at an elevation of 4,733 meters (15,528 feet) above the sea level. It's the highest border-crossing in the world and the highest point on the Karakoram Highway.
Khunjerab Pass is located in the Karakoram Mountains in a strategic position on the northern border of Pakistan's Gilgit–Baltistan Hunza-Nagar District on the southwest border of the Xinjiang region of China. For comparison, Mont Blanc, the tallest mountain in Western Europe, is 4.810 m and Mount Whitney, the highest point in the 48 contiguous United States, is 4.421.
This section of the road was completed in 1982 and is possibly the highest metalled border crossing in the world. On the Pakistani side, the surface of the road is gravel. On the Chinese side, the surface of the road is a bad asphalt.
During the rainy season (December-April), because of mudslides the pass is closed to all vehicles except large trucks. The long, relatively flat pass is often snow-covered during the winter season and as a consequence is generally closed from November 30 to May 1. Choose your time carefully. The road bad conditions, with extremely large pot holes could potentially pop a tire, crack a rim, or screw up your cars allignment. There are some police checkpoints along the highway in China that may slow down your journey significantly if there are many cars and trucks.
Road condition is deteriorating with every passing year so average speed will be less than 40 km/hour. There are some important rules for these kind of roads: big trucks have the right of way, always drive with your headlights on so others can see you, keep your headlights and taillights clean so they are visible, stay on the right side of the road, don't stop on bridges or hills, check your rear-view mirror regularly, especially before stopping, if you spot wildlife, pull over to a safe spot to park and slow down when passing other vehicles (especially bicyclists and motorcyclists) to lessen the chances of hitting them with mud or flying rocks from your tires. It is not advisable to take cars, 4x4 is preferred but a Van / coaster would serve the purpose.
The surface on this gravel road is often loose, especially along the sides of the road. It makes necessary to drive carefully and slow down whenever approaching an oncoming car. Besham is the start of Kohsitan which is famous for its ruggedness and stubbornness. It is highly advisable to limit your stay and keep going preferably during day time. Kohistan borders Baltistan which is relatively safe. Main town to stay overnight is Chillas. This relatively flat and well signposted mountain highway is the highest international road in the world and includes the world’s highest international border crossing, the Youyi Friendship Bridge and access to the stunning Karakul Mountain Lake. The road is generally closed during the Winter months owing to snow making it impassable. Don’t forget your passport.
Pic: Travelling Pakistan