Among the Connected Vehicle (CV) applications developed under the Applications for the Environment: Real-Time Information Synthesis (AERIS) program, the Eco-Approach and Departure at Signalized Intersection (EAD) application has shown great promise in terms of reducing fuel consumption and pollutant emissions. The EAD application utilizes signal phase and timing (SPaT) information from the upcoming traffic signal to determine a recommended speed profile minimizing vehicle energy consumption and pollutant emissions when approaching and departing from a signalized intersection. The recommended speed profile is then conveyed to the driver through driver-vehicle interfaces (DVIs). However, a driver may not be able to precisely follow the recommended speed profile, resulting in degraded effectiveness of the application. Partial vehicle automation could help drivers comply with the suggested speed profiles, even at Level 1 (function-specific automation) or Level 2 (combined function automation) automation.
In this study, a partially automated vehicle system with an eco-approach and departure feature (called the GlidePath Prototype), which can receive dedicated short-range communication (DSRC) message sets from the intersection and automatically follow recommended speed profiles, was developed, demonstrated, and evaluated.
Compared to manually following the speed profiles recommended by the EAD application, the GlidePath Prototype reduced fuel consumption by an average of 17 percent. In some scenarios fuel savings could be as great as 40 percent with a travel time reduced by up to 64 percent.
Driving comfort may also be improved as the speed profiles are smoothed by the automated application.