evidence: Prime Minister Narendra Modi today inaugurated the country's longest highway tunnel - Chenani-Nashri [...] Prime Minister Narendra Modi today opened India's longest road tunnel on the Jammu-Srinagar National Highway, which cuts short the journey between the two cities by 30 km and reduces travel time by two hours. Built at an altitude of 1,200 meters, at a cost of Rs 3,700 crore, the Chenani-Nashri tunnel will ensure a safe and swift passage for commuters, even in adverse weather conditions. The tunnel is among the longest highway tunnels in Asia. The Prime Minister, who arrived in Udhampur, the headquarters of the army's Northern Command, by a special plane for the inauguration, took an army helicopter to Chenani. [...] The Chenani-Nashri tunnel is India's first and the world's sixth tunnel to have transverse ventilation system, providing fresh air to passengers. Ventilation systems for such long tunnels are essential to maintain clean air, permissible carbon dioxide levels and expel harmful vehicle emissions.