Thousands of machines and equipment were mobilised; More than 1,000 workers and engineers worked around the clock; Over 1,350 construction days and nights; Those are some of the impressive figures posted during the construction of the Hai Van Tunnel 2, the longest road tunnel in Southeast Asia. The Hai Van 2 Tunnel has a total length of more than 12.4 km, of which the tunnel itself stretches nearly 6.3 km through a mountain, with two sections for vehicles, each 9.7 metres in width. The north approach road is about 1.7 km long and the south approach road 4 km. The tunnel is equipped with modern equipment to ensure traffic safety, including more than 1,500 sets of LED lights, 580 sensors, 16 reversible fans, and 174 traffic surveillance cameras, among others. The tunnel is expected to help cut traffic congestion on the exiting Hai Van Tunnel 1 and will also shorten travel times and improve the efficiency of passenger and goods transport./.