A Study of Coordinated Signal Control Considering Speed Control of Automated Vehicles

Abstract

In this study, we construct a simplified model of the speed control of an automated vehicle (AV) to avoid stopping a platoon of following vehicles in a coordinated signal-controlled corridor in which manual and automated vehicles are mixed. We then analyze how signal delays, number of stops, and CO₂ emissions vary depending on the AV penetration rate and signal parameters such as the (common) cycle length and offset. The analytical formula of the above three performance indicators and numerical results showed that (i) appropriate setting of the speed control interval of the AV can reduce the number of stops and CO₂ emissions without changing the signal delay, (ii) CO₂ emissions can be significantly reduced when the cycle length is relatively small and the offset is unfavorable from the viewpoint of the number of stops, and (iii) therefore, a small cycle length is desirable to maximize the effect of the AV speed control.