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 at the English portal, caused concerns. Identified by the 1964–65 geophysical survey, the Fosse Dangaered is an infilled valley system extending below the seabed, south of the tunnel route in mid-channel. A 1986 survey showed that a tributary crossed the path of the tunnel, and so the tunnel route was made as far north and deep as possible. The English terminal had to be located in the Castle Hill landslip, which consists of displaced and tipping blocks of lower chalk, glauconitic marl and gault debris. Thus the area was stabilised by buttressing and inserting drainage adits. The service tunnel acted