The purpose of this study is to apply the growth mechanism of plant to sensing system. In this paper, the one-output for two-input sensing device imitating the mechanism of photosynthesis is introduced. As one example of the device applications for a transport system, an automobile which recognizes the driving environment is presented. As a result, the possibility of applying the photosynthesis mechanism for engineering is shown by proposing the quantitative setting of automobile speed which generally depends on the intuition of a driver.