Impacts of Varying Market Penetration and Level of Autonomy of Connected and Automated Vehicles

Human factors stand as the foremost contributor to crashes. The ongoing rapid progress in automation technology has the potential to reduce human errors and create a safer transportation environment. In the near future, the roads will see a mix of traditional Human Driven Vehicles (HDVs) and Connected and Automated Vehicles (CAVs) with varying levels of automation and market adoption. As technology advances, it becomes clear that as market adoption of CAVs increases, so does their level of automation. While many studies have looked at the effects of CAVs, most have focused solely on market penetration or automation levels in isolation. Only a few have examined both market adoption and automation together, especially at different stages of CAV integration. Very few have explored these combined effects on highways. This study aims to explore how this mixed traffic—comprising HDVs and CAVs with different Market Penetration and Level of Autonomy (MPLA)—affects safety and operational efficiency. To do this, the study employed a simulation model using VISSIM that mimics mixed traffic with different MPLA settings. Altogether 27 scenarios with varying traffic volumes and MPLA Levels were explored, assessing safety using the Time to Collision indicator with three different thresholds. The findings showed that CAVs with mid to high automation, combined with a market penetration rate of about 50%, reduced conflicts by about 50% in medium to high traffic volumes while improving network efficiency. In scenarios with higher MPLA, the system performed consistently well, with minimal variations in safety and operational impacts across different traffic volumes. These results highlight the effectiveness of CAVs with higher MPLAs in managing traffic.