Disney (the man) was fascinated by cities, and towards the end of his life he kept only one planning book at his side, "The Heart of our Cities" by Victor Gruen:
"As Gruen suggests, 'One of the primary purposes for a city is to bring together many people so that, through direct communication with each other, they may exchange goods and ideas without undue loss of energy and time.' Walt wanted to take this idea one step further. At EPCOT guests would be invited to participate in his experimental community and to take the lessons learned back home with them."
EPCOT was to have a significant underground network of roads and transit systems, coming together in a massive transportation hub.
"Walt and Gruen were strong advocates for separating all mechanical and utilitarian functions away from the public realm."