[Vienna, September 22. Image via Getty]

An Austrian woman walks on an empty main road called ''Burg Ring '' shortly after it was closed for eight hours to participate in Europe's Car Free day in the heart of Vienna on September 22, 2009.The closure of the street caused traffic chaos in several parts of Vienna.AFP PHOTO/Joe KLAMAR (Photo credit should read JOE KLAMAR/AFP/Getty Images)