National Highway 3, or NH 3, is a national highway in India. It starts from Atari adjacent to the India-Pakistan border near Amritsar and terminates at Leh in Ladakh, via Manali in Himachal Pradesh. The highway passes through Rohtang Pass, climbing a high altitude of . Now the long Atal Tunnel helps in vehicles avoiding Rohtang Pass. Next this highway passes through Bara Lacha La or Bara Lacha Pass climbing a high altitude of & again passes through Taglang La or Taglang Pass climbing a serious altitude of . This makes NH-3 the most dangerous road in the world. In winters, this highway faces severe situations. Border Roads Organization known as BRO maintains this highway 24X7 throughout the year. The Headquarters of BRO 38 Battalion is situated in Manali who are tasked with maintaining NH-3 in Manali-Leh stretch.
After renumbering of all national highways by National Highway Authority of India in 2010, parts of the former NH 1 and NH 70 have been combined with parts of former NH 21 to create the new NH 3.
Part of national Highway 3 runs through the upper reaches of Himachal Pradesh and Ladakh, crossing some high elevation mountain passes. First major pass comes after Manali, which is Rohtang pass at an elevation of 3,978 m. Rohtang pass provides connectivity between the Kullu valley and the Lahaul and Spiti valleys of Himachal Pradesh. Next major pass on NH3 is Baralacha La at an elevation of 4,890 m in Zanskar range. In Leh district, NH 3 crosses over Nakee La (4739 m, 15547 ft), Lachulung La (5064 m, 16616 ft) and Taglang La.
National Highway 3 route runs through three states.
Attari, Amritsar, Jalandhar, Hoshiarpur - H.P. border (256 km).
Punjab border - Gagret, Amb, Nadaun, Hamirpur, Tauni Devi, Awah Devi, Sarkaghat, Kotli, Mandi, Kullu, Manali, Gramphoo, Kyelong - J & K border (534 km).
H.P border - Leh (200 km).
Process for upgrading of road from two to four lanes on Jalandhar to Hoshiarpur section was started by NHAI to improve connectivity. Traffic congestion is encountered at Adampur and Rama Mandi on this 58 km stretch. 39.4 km of this project is assigned to the public works department, Punjab.