Karakoram Highway (Pakistan-China): 1300km, climbing to 4714 metres at Khunjerab Pass. Construction cost over 1000 lives.
Pamir Highway (Tajikistan-Kyrgyzstan): 1200km M41, crossing at 4655 metres Ak-Baital Pass. Gravel stretches, rockfall and altitude sickness.
Transfagarasan Highway (Romania): 90km serpentine masterpiece, topping at 2042 metres. Top Gear crowned it "best road in the world".
Ruta 40 (Argentina): 5200km from sub-tropical Jujuy to ice-clad Patagonia, climbing above 4900 metres.
Sani Pass (South Africa-Lesotho): 9km track scaling 1332 metres with 1:3 gradients. One of the most dangerous mountain passes in the world.