On this research paper the (COrn2rn) emission reduction from the operation of Addis Ababa-Djiboutirnelectric railway line project of replaced truck trailer is studied, discussed and quantified. Emissionrnreduction mechanism is applicable by one of globally accepted environmentally friendly, zerornemission development option of the electric train railway project. Due to the application of this lifernsaving project it is expected that a great reduction in motorized vehicles from road transport in thernratio of 1 electric train = 50 long trucks that consumes different fuel types which helps to emitrncarbon dioxide (COrn2rn) and other toxic gases. The mode shift effect procedure and method appliedrnto estimate the energy and (COrn2rn) emission avoided by the implementation of this project. Thernprocedure developed is determined 7.707 M ton of CO2e will be saved emissions in the projectrnyear of 18 years from (2017-2035) which is applied to Addis Ababa-Djibouti electric railway andrnthe saved energy is 1.10E+11 KWH (384 million GJ energy, with much 95% of this energy isrncorresponding to non-renewable energy. Each fright (container, and bulk products) kilometer willrnresult in avoid emissions(gCOrn2rn)and avoided non-renewable energy consumption of Ethiopiarn(specifically on the constructed railway line of The Addis Ababa-Djibouti corridor which is the rnmajor import and export corridor of the Country handling more than 90% of the foreign trade. rnIn addition, on the project year Ethiopian truck trailer will consume a total of 2,613,308,212 literrndiesel fuel with its direct tail emission of 6.3190 MT COrn2rne if vhicle were used. The life cyclernanalysis GHG gases amount total of 2.5 MT of COrn2rne from fuel extraction, refining plant,rntransportation and leakage are found by using GREET life cycle modeling software. Moreover thernemission from service of 30 year or (6,000,000 km travelled) life cycle of fright vehicles of trucksrnare analyses based on the existing collected data. A total of 0.00614599 M ton of COrn2rne from servicernare carried out. The Microsoft Excel software the GREET life cycle modeling software package isrngreatly used in the analysis of different data. Finally a Microsoft Excel software program(GHG emission calculator) are prepared that will bernused for anyone to find out the average fuel consumption, LCA emission from vehicles service,rnemission from electricity generation and COrn2rne emitted gas with its percentage of COrn2rnrnand SFrn6 rnby using an input of ton and kilometer variables.