Brake Dynamics Effect on AHS Lane Capacity

Highway automation is a topic of active research due to its promise of solving the congestion problem on the nation's highways. It is thus necessary to evaluate the benefits of such a system. One of the most important projected improvements is the increase in capacity and safety. However, the actual capacity increase is highly dependent on the performance of each sub-system used. This paper attempts to investigate the effects of brake system dynamics and inter-vehicle communication delays (microscopic characteristics) on the capacity of the system (macroscopic characteristics). Simulations were conducted to investigate the relationship between the microscopic and macroscopic characteristics and random variations from vehicle to vehicle within a platoon. Recommendations were made regarding the maximum desired delays, intra-platoon and inter-platoon distances and platoon size in order to achieve the highest possible capacity while maintaining a high degree of safety.