The Leh-Manali Highway, one of the two routes to Ladakh, The Rohtang Pass receives heavy snowfall and blizzards during winter months and is open for road traffic for only four months in a year. The tunnel will keep the highway open during the winter. The other route to Leh is through the Zoji La pass on the Srinagar-Drass-Kargil-Leh highway which also gets blocked by snow for nearly four months in a year. Construction of a 14 km long tunnel under Zoji La pass has been planned. These two routes are vital to feed military supplies into military sub-sector in the west facing Aksai Chin and the Siachen Glacier.