A case study was conducted by analyzing floating car data from throughout Japan to determine the CO2 reduction potential due to traffic-flow smoothing and eco-driving promotion. The data used in this study is from hybrid cars equipped with Eco Assist, which has been reported in past studies to enhance fuel economy by approximately 10% as the number of driving times increases. First, multiple regression analysis was performed on the subject floating car data to obtain a polynomial with fuel economy as the explained variable and items related to traffic flow and eco-driving as the explanatory variables. The explanatory variables set the present distribution and the distribution under the assumed conditions of eco-driving promotion and smoothed traffic flow. These assumed conditions were applied to the polynomial to obtain the fuel economy frequency distributions for the present and assumed conditions, and the CO2 reduction potential was calculated from the difference between the two. The assumed conditions were calculated to have a fuel economy enhancement potential of 18%, mainly due to traffic-flow smoothing. On the other hand, eco-driving was calculated to have fuel economy enhancement potential of 1% over and above the approximately 10% enhancement of Eco Assist. In addition, it was found that 2/3 of the CO2 reduction potential was enhancement when driving at a travel speed of 30 km/h or less.
Article of Honda R&D Technical Review Vol.24 No.2 (134 - 140)