Himachal is connected by air from Delhi to Shimla, Kangra and Kullu. Being a Hilly state and having difficult terrain, railway is not possible. However there is a narrow gauge rail line from Kalka to Shimla and Pathankot to Joginder nagar. The most important mode of transport therefore is buses for people and trucks for loads. There is a net work of roads throughout the state where buses of all types operate for the locals and tourists. There are truck unions for regulating the carriage of goods from one place to another. Being a tourist state, luxury coaches and cars also ply during the season.