Acadia National Park Improvement Act of 2005 - Extends the Acadia Park Advisory Commission.
Increases the ceiling on the amount of appropriations for the acquisition of lands and interests with respect to the Acadia National Park.
Directs the Secretary of the Interior to provide assistance in the planning, construction, and operation of an intermodal transportation center located outside the Park's boundary, in the town of Trenton, Maine, to improve the management, interpretation, and visitor enjoyment of the Park.