NNR (Nishi-Nippon Railroad Co. Ltd.) introduced the downtown one-dollar circuit bus in Fukuoka City, Japan in July 1999. NNR first announced that it was an experiment until March 2000 while it could be continued as a business after the experimentation period if its operation record would pass the given criteria of profitability. Surprisingly, during past 8 months, the downtown one-dollar bus has attracted over 1.8 times as many customers as before. NNR has decided to keep on running the downtown one-dollar bus as a business from April 2000. The purpose of this paper is to estimate the economic impact of the downtown one-dollar bus at city center retail environment of Fukuoka City based on data obtained from surveys on consumer's shop-around behavior conducted in March 2000.