In December 1996, TransCanada PipeLines Ltd. (TCPL), Calgary, selected and used a geographic-information-system (GIS) approach developed by Earth Information Systems Corp., Austin, Texas (Eisys), to automate the route selection for a TCPL expansion. Pipeline route selection is a strategic component of a transmission company`s expansion activities. The selection process begins with a feasibility study and an assessment of the alternative routes to link source to market. The selected route can significantly affect the success or failure of a project, depending on its public acceptance, economics, and construction impact. Critical issues affecting route selection are societal risk, environmental impact, and engineering and operational efficiency. The use of GIS makes possible simultaneous consideration of these issues.