Transportation is one of the most important and valuable assets of any country in meeting the needs of the growing population and can be a solid backbone for its economic growth. Lack of foresight and basic and field studies to develop this industry will cause many problems in the development and fulfilment of vital needs of the people of society, and perhaps one of the best and, at the same time, most controversial issues in this regard is the safety issue in designing roads.
One of the natural disasters that reduces the safety of roads is the landslide phenomenon. The slippage or thrust of soil masses in sloping lands can be studied under four specific categories: Slidiiy or slippage, Greep or soil crawl, Fall or fall of rock and soil, and Flows or flowing streams on steep lands. Every year this phenomenon causes financial losses and, in some cases, it unfortunately brings about great number of casualties in our country, destroys boundaries of roads, monuments and other infrastructures, and the government is forced to pay enormous amount of money to compensate the devastations and relocate masses of soil. For example, in the earthquake caused by the activation of the Baladeh fault on the May 26, 2004, what caused the destruction of the northern roads near the earthquake’s epicenter, especially the Chalous-Tehran road (Kanduvan route) and, unfortunately, death of twelve people, was the landslide phenomenon that was caused by the earthquake.