A framework for integrating stakeholder preferences when deciding on power transmission line corridors

Decisions about urban space and especially regarding power transmission lines are of great public interest, because their visibility affects citizens for decades. With citizens’ increasing awareness, they expect to be transparently informed, their concerns to be taken seriously and that decision-makers base their decisions rationally on facts and laws. In this paper, we present a 3D Decision Support System (3D DSS) that tackles this issue and allows decision-makers to find an optimal transmission line corridor on such rational basis and by considering 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 which graphic representations may support decision-makers firstly in evaluating a transmission line corridor modeled by the 3D DSS, secondly in considering and improving a human-defined scenario for transmission line planning, and thirdly in changing their opinion about a human-defined path. For this, a questionnaire was statistically evaluated by means of exploratory analysis, correlation analysis, and regression analysis. The results on the investigated visual analytics 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. As our new approach allows stakeholders to evaluate a transmission line path they consider to be optimal for land and population, it has a high potential for supporting rational group decision-making when considering different opinions.