The SEA is an important assessment tool is decision making. From the case study, it is apparent that incorporating all the social, economic, ecological and project concerns , is critical for every project. SEA brings together different stakeholders, and this is very effective for decision making. The Spatial Multi Criteria Evaluation (SMCE) tool, uses input maps which must satisfy a number of factors and constraints for site selection. It is invaluable, since stakeholders identify feasible needs and prioritize them. Moreover, they help in sound decision making and provide useful information, that otherwise would have been overlooked, and this enables the decision makers to know the real cost of a project. For example, in the Lapsset project, economic, ecological, social, and project visions were accomplished by selecting the important aspects within each vision and assigned weights on each, and the end product was a composite index map for each vision. The results of the visions were accurate despite the spatial resolution of the data. This also enabled the generation of a proposed route based on the lapsset route and different vision routes. The proposed route will improve the development of the northern frontier.