In old days when modes of transportation were not there, people used to walk to the places they wanted to reach. For transportation of goods, bullock carts, camels, horses, etc. were often used. All this was meeting the mobility requirements as the settlements were not too dispersed. With the rapid advancement in the development of tall building and public facilities, it became paramount to address the need to transportation of pedestrians and also of goods.  With multi-storeyed buildings or large shopping complexes or airports, it is unreasonable to expect the user to travel across the buildings/ public facilities by means of walking alone, at least not in a timely manner. Towards this end, innovations sprung up facilitating movement of pedestrians as well as goods in large shopping malls, multi-storeyed residential buildings, airports and other public facilities.