Potential Impacts of Connected and Autonomous Vehicles on Controlling Criteria for Road Geometric Design: A Review

Abstract

The development of connected and autonomous vehicles (CAVs) has progressed rapidly with advancements in intelligent transportation systems, automated driving technologies, and regulatory reforms worldwide. As the efficiency and safety of surface transportation heavily rely on highway geometric design, understanding the impact of CAVs on design control elements is essential to fully capitalize the benefits CAVs may offer. The objective of this study is to conduct a comprehensive review of existing literature to synthesize how CAVs can influence the controlling criteria for highway geometric design. Over 30 articles were thoroughly reviewed to gain insights into the impacts of CAVs on highway design and potential explanations for them. As CAVs could potentially reduce the minimum required stopping sight distance, they create opportunities to decrease other geometric dimensions, such as horizontal curve radius, length of vertical curves, horizontal sight offset, extra widening, and so on. However, this optimization is more feasible in an environment with fewer human-driven vehicles. Moreover, further related research needs to be done in mixed traffic streams and complex driving conditions. The critical discussions of this study can offer valuable insights, shedding light on the potential benefits and implications that an automated transportation sector may bring to future road geometry design.