Assessing the impacts of heavy vehicles on traffic characteristics of highways under mixed traffic platooning conditions

Abstract

The study aims to investigate the impact of heavy vehicles (HVs) on traffic characteristics under platoon conditions on Indian highways. Traffic volume, speed, and time headway data were gathered from different highway sections using infra-red sensors. The mean relative speed criteria were used as an indicator of variability to estimate the critical time headway. The threshold value of a critical time headway of 4 sec was determined to represent vehicles into non-platoon followers and platoon followers. The speed-flow-density model curves were developed for two different traffic regimes, one without platoons and the other with platoons created by the HVs. The results show that under platoon conditions, the speed at capacity, density at capacity, and traffic capacity reduced by 11.2%, 12.5%, and 22.3%, respectively, compared to non-platoon conditions. Additionally, the average travel time and travel delay increased by 18.1 s/km and 12.7 s/km, respectively. The study's findings emphasize the importance of considering platoon dynamics under the influence of HVs to better understand their impact on traffic characteristics.