Abstract

Transmission line routing plays a crucial role in the planning and development of electricity transmission infrastructure. Traditional approaches to route selection often concentrate on finding a single route, potentially overlooking optimal solutions and not fully capturing the complexities and trade-offs inherent in the process. In this paper, we propose a novel methodology for generating optimal alternatives for transmission line routes, designed to provide realistic options for decision-makers in real-life transmission planning studies. Our approach integrates advanced optimization techniques with geographic information systems (GIS) and multi-criteria decision analysis (MCDA) to systematically explore and evaluate route alternatives based on technical, environmental, social, and economic criteria. By generating a diverse set of realistic routes, the methodology enables decision-makers to make informed choices that balance competing objectives and the interests of different stakeholders. Through a case study in Chile, we demonstrate the ability of the proposed methodology to produce route alternatives that represent various preferences across techno-economic and socio-environmental factors. By offering a comprehensive set of options, this methodology supports stakeholders in selecting routes that fulfill infrastructure needs while addressing economic, societal and environmental concerns. © 2025 Elsevier Ltd