We consider an eco-driving technology that can reduce fuel consumption and emissions at 2 signalized intersections by using Infrastructure-to-Vehicle (I2V) communication system. In this 3 paper, eco-driving behaviors of human drivers and automated vehicle were evaluated based on a 4 driving simulator. To minimize the deceleration or avoid the complete stop at the traffic signals, 5 and to ultimately eliminate unnecessary fuel consumptions, the eco-driving guidance provided 6 drivers with speed profile derived from current velocity, distance to the intersection, and remaining 7 green or red time. A total of 43 drivers participated in the driving simulator-based experiments by 8 following the base case and the eco-driving case. At the first experiment, the results showed that 9 the performance of the eco-driving varied a lot by the individual participants. This was because the 10 participants did not closely follow the eco-guidance. At the second experiment, randomly selected 11 8 drivers were given more time to become comfortable with the interface before the experiments, 12 as well as incentives to motivate them to follow the eco-guidance interface. The second 13 experiment results showed statistically significant about 5% improvements in fuel consumption 14 and emissions reduction over the base case. When the eco-driving case was compared with an 15 automated vehicle case, the automated vehicle improved fuel consumption and emissions between 16 18-20% over the human-driven eco-driving case. 17 18