Evaluation of Providing Recommended Speed for Reducing CO2 Emissions from Vehicles by Driving Simulator

Idling time at a signalized intersection increases the amount of CO2 emissions from vehicles. If drivers would be informed of the signal change prior to the change of the signal ahead from green to amber/red, they could decelerate in advance and reduce their idling times at the intersection. In this study, we develop an information provision system with a 3D driving simulator. The system provides the recommended speed, which is calculated based on the distance from the signal ahead and the current vehicle speed, and the indication to release an accelerator pedal. If a driver follows the recommended speed or the accelerator-off indication, one can pass through the intersection ahead without stopping or reduce an idling time. By this driving simulator, we verify the effectiveness of providing the information to a driver for reducing CO2 emissions under some scenarios of the information provision. As a result of the experiments, it was found that the information provision reduced the amount of CO2 emissions in comparison with the result of no information provided. The maximum reduction of the CO2 emissions was 6.1% and 5.4% with the accelerator-off indication and the recommended speed, respectively. It indicates that providing the information is effective for reducing CO2 emissions from vehicles approaching a signalized intersection.