ABSTRACT
Decision-making on any transportation project has to follow a detailed Techno -economic analysis. This is particularly significant in respect of tunnels and bridges which are the most expensive parts of civil engineering structures on a roadway or railway project. A length of road/track through a tunnel may cost up to even 10 times the cost of the road/track on plain land and 4 to 6 times that of the same in a cutting open to sky in hilly areas. Hence tunnels can be justified only by the compensating savings in terms of distance, time of travel and operating cost for the volume of traffic to be handled. Saving in length of road/ line will have a direct effect on the savings in length of haul and indirectly on operating costs in order to offset high construction costs.
