The Arlberg Road Tunnel (German: Arlberg Straßentunnel), with a length of 13.976 kilometres (8.684 mi), is Austria's longest road tunnel. When it was inaugurated, it was the longest road tunnel in the world. It carries the S16 Arlberg Schnellstraße (German for "Arlberg Highway") under the Arlberg massif from Tyrol to Vorarlberg.
It was built between July 1974 and December 1978, and its costs amounted to 4 billion Austrian schillings (~300 million €). The tunnel is designed for 1800 vehicles per hour and equipped with 4 ventilation centres (one shaft with a height of 736 metres is the deepest in Europe), 12 vents, 43 cameras for traffic monitoring and 16 niches. In 1998 the tunnel was used by 2.6 million vehicles, where 18% are accounting for freight transport. The Arlberg Tunnel is a Toll Road with a one-way fee of €10 (as of December 2018). Tolls for both directions are collected at the eastern end of the tunnel.