Ethiopia, located in the Horn of Africa, is largely mountainous in topography. The Ethiopian landformrnis characterized by great diversity. There are flat-topped plateaus, high and rugged mountains, deep riverrngorges and rolling plains. Constructing surface road on such greatly undulating topography is so difficult.rnTo traverse such kinds of terrain, there may be a need of consructing a bridge or increasing the routernlength by changing the route direction and/or excavation to arequired level of grade according to therndesign standard of ERA or AACRA. Therefore, it is important to search for an equivalent but bestrnalternative solution to traverse such kind of topography. As the economy of the country shows arnconsiderable progress, the road infrastructure plays a great role. Road infrastructures have noticablernimpact on socio-economic development of the nation. Road projects, particularly tunnel road projects,rnsavings of time for motorists or commuters, accident reduction, user cost saving and reduction of CO2rnare often the major benefits. These all benefits have a great impact on the GDP of the country directlyrnor indirectly. Specially, the saved time create two areas of contentions. One is predicting what the timernsavings would be for the road user; the other is estimating what those times savings are worth to therncommunity and even the countries GDP. Converting these benefits which get off by constructing tunnelrnroad to displace the Entoto mountain, the enumerable out put of Benefit-Cost ratio of 3.07:1, an NPV ofrn15,674.38 METB and an IRR of 36.0 percent, which shows that the project have a greate impact therncounty GDP. This implies that the Entoto tunnel road is the best alternative transportation system forrnareas or the country. In general, even if tunnel roads constitute costly infrastructure in terms ofrnconstruction cost throughout the world, however, from Ethiopian topography point of view, constructingrntunnel road is the feasible and sustainable alternative. The costs of construction of tunnel road project inrnEthiopia instead of surface road in mountainous and escarpment terrain is offset by economic benefitsrnof travel time saving, user cost saving, urbanization development in the surrounding areas of the citiesrnand towns of Ethiopia like Addis Ababa, enhancing traffic fluidity along the route, increasing divertedrnand induced traffic to developed area due to the tunnel project, comfort, safety, reliable routes (mountainrncrossings) as well as the overall reduction of the environmental impact on the surrounding areas.rnTherefore, constructing tunnel road in Ethiopia is an effective and efficient alternative transportationrninfrastructure from its topography point of views.