How does driving behavior change when following an eco-driving car?

To realize the sustainable transportation system in Japan, the issue to reduce CO2 emission made by the automobiles has become very serious. Among the countermeasures discussed and proposed, the eco-driving has been treated as very important and believed to be very effective. The eco-driving means changing the driving styles to be much more economically and ecologically. This does not only apply to the cars doing the eco-driving but also affect the cars following the eco-driving cars. Furthermore, by considering most of the studies up to now had been based on the computer simulations and there had been only a few studies that were based on the real situation, we conducted a test run by using vehicles on the public roads under the normal traffic conditions. This paper is to report a part of the results of our test run. The driving data were recorded by the on board unit FCM-GPS MMC produced by TECHTOM being used together with EC15WWF-40. The driving behaviors of the followed cars were recorded by the video camera taken from the back window of the last car of the eco-driving vehicle queue. The analysis mainly on that how many cars kept in following and how many cars gave up the following and then overtook the eco-driving car. As a result, we found that whether the following cars change their behaviors also depends on how perfect the followed car does the eco-driving. Here, the eco-driving is described by three indicators: tenderly starting, less change of speed and early accelerator off. Moreover, whether the eco-driving car has a sticker or not affected the behavior of the following cars, too.