"The ministry says average traffic volume on toll-free sections of the expressways doubled compare to one week before the start of the experiment. Among highways seeing increased traffic, the ministry says a section of the Tohoku-Chuo Expressway in Yamagata prefecture was 4.5 times busier on weekdays."
Source: Toll-free highways see traffic double
2010/08/12
NHK WORLD
http://www.nhk.or.jp/daily/english/12_16.html