Review

In this paper, we present a 3D Decision Support System (3D DSS) that computes the optimal transmission line corridor and path for a new overhead line based on legal requirements and based on a stakeholder's preferences regarding multiple criteria. We examined its reliability regarding the ability of predicting transmission line corridors realistically --- as stakeholders would expect them --- by carrying out a study in central Switzerland with 10 grid planning experts and government representatives. Moreover, we investigated the extent to what graphic representations such as an interactive 3D environment including virtual maps or spider charts representing the extent to what subjective goals have been achieved may support decision-makers in evaluating a transmission line corridor modeled by the 3D DSS, in considering and improving a human-defined scenario for transmission line planning, and in changing their opinion about a human-defined path. For this, we statistically evaluated a questionnaire by means of exploratory analysis, correlation analysis, and regression analysis. 

Our results show that the initial expectations of the 3D DSS were high and have been fulfilled to a great extent. Second, the results on the investigated visual analytic approach showed that it supports the evaluation of the corridor modeled by the 3D DSS as well as of the scenario defined by the stakeholders. We assess our new approach, which allows stakeholders to evaluate a transmission line path they consider to be optimal for land and population, a high potential for supporting rational group decision-making when considering different opinions.