honky tube 

Private, enclosed, climate-controlled, elevated walkway that connects two or more buildings. So named for the tendency of white office workers to use them and avoid contact with the street below, where people of color congregate.

"The skywalk system connecting the buildings and interior space of the Peachtree Center complex was the most controversial aspect of the project. Called "honky tubes" by local African-Americans, the skywalks tend to segregate the mostly white visitors rather than encouraging them to experience the life of the city outside the buildings."

Source:
Paul Kantor, Dennis R. Judd
American Urban Politics in a Global Age: The Reader, p. 195
Longman, c2007

honky tube by William Whyte Fan September 28, 2008