The economic appraisal of transportation projects is interlinked with cost - benefit analysis (CBA), as it is a main index
regarding the value of investment [33]. Through a comparison between costs and benefits by using the benefit cost ratio
(BCR), the economic net present value (ENPV) and the economic rate of return (ERR), the social value of the project
can be produced. The value of travel time savings is considered to be a key characteristic for transport studies as it
occupies 50-70% of the total benefit [29][40]. Vehicle operating costs (VOCS) are accrued by multiplying the default
operating cost per vehicle kilometre by the number of vehicle kilometres saved by the project [41]. The methods, which
are intended to evaluate the non-user benefits related to the prevention of accidents are referred to as the average danger
levels according to transport mode, while the environmental externalities generally depend upon the travel distances
and exposure to polluting emissions [6].