Mention the major function of the Border Road Organisation (BRO).

The strategic roads of the northern and north-eastern border areas are constructed and maintained by the Border Roads Organisation. BRO was established in May 1960. Its main focus was enabling economic development and establishing defence preparedness by the prompt and harmonised development and improvement of strategically important roads along the northern and north-eastern boundary of the country. It has constructed roads in high altitude hilly terrain by joining Chandigarh with Manali and Leh. It is also responsible for snow clearance in high altitudes.