Anzob Tunnel Road. It is also a transit route between Dushanbe and Uzbekistan's capital Tashkent. Prior to construction of the tunnel, especially during winter, the threat of year-round avalanches led to periodic disruptions of commerce. The tunnel was officially opened in March 2006; it was built by the Iranian Sabir Co. Due to the significance of the tunnel, limited traffic flow was permitted via signing a waiver form noting potential hazards such as flooding and smog from construction equipment operating inside the tunnel prior to the final construction phase which may have included installation of ventilation and drainage infrastructure. As of May
Channel Tunnel train's winterisation shields, and the transition from cold air outside to the tunnel's warm atmosphere had melted the snow, resulting in electrical failures. One train was turned back before reaching the tunnel; two trains were hauled out of the tunnel by Eurotunnel Class 0001 diesel locomotives. The blocking of the tunnel led to the implementation of Operation Stack, the transformation of the M20 motorway into a linear car park. The occasion was the first time that a Eurostar train was evacuated inside the tunnel; the failing of four at once was described as "unprecedented". The Channel Tunnel reopened the following