The tunnel is a relief, so that you don't have to drive over the Anzob Pass, but you can also take this tunnel in the car or bus and not on the bike. Construction of the tunnel began in 1988 during the Soviet era and was continued in 1999 by an Iranian consortium. The tunnel was opened in 2006, but until 2015 the passage was an adventurous undertaking. The tunnel was not lit and there was no ventilation system. The biggest problem was the water in the tunnel, some of which was up to half a meter high. In 2015 the tunnel was closed, Iran was obliged to remedy the shortcomings and was reopened in November. de.wikipedia.org/wiki/Ansob-Tunnel