main street

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The principal street of a small town.
• noun Average businesses and households considered as a group.
• noun The inhabitants of small US towns considered as having a narrow-minded or materialistic worldview.

from the GNU version of the Collaborative International Dictionary of English.

• noun A main thoroughfare, usually one in a small town having the largest concentration of retail businesses.
• noun The attitudes, environment, or life style of a small town; -- usually capitalized, and often used attributively.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun street that serves as a principal thoroughfare for traffic in a town
• noun any small town (or the people who inhabit it); generally used to represent parochialism and materialism (after a novel by Sinclair Lewis)