Dedicated autonomous vehicle lane measure for development of autonomous vehicles: A system dynamics approach

Different from the stage of full use of human-driven vehicles (HDVs) or autonomous vehicles (AVs), the mixed use of AVs and HDVs represents a special transition stage. Interaction between HDVs and AVs presents a challenge for urban transport development, especially during the initial transition stage. Dedicated AV lane (DAVL) measure has been proposed for promoting development of AVs. This study focuses on the impact analysis of implementing DAVL measure under heterogeneous commuting conditions, which are characterised by varying automation levels and evolving AV market share. A system dynamics framework is developed to integrate the DAVL deployment with dynamic shifts in vehicle market adoption and commuting conditions. Specifically, macro-level commuting indicators are examined, i.e., average commuting speed and congestion degree, as AVs with varying automation levels progressively enter the market. Scenario analyses are based on the high-level autonomous driving demonstration zone in Yizhuang new city (YNC) of Beijing, they indicate that DAVL measure has a significant impact on AV market share, and positively influencing AV market development. However, with increasing AV market share, the initially superior commuting performance delivered by DAVL is gradually eroded, manifested by shrinking improvements in average commuting speed and weaker reductions in congestion degree. Moreover, the fixed DAVL approach results in uneven utilisation of road space, i.e., the congestion degree on regular lanes shifts from oversaturation toward underutilisation, whilst the congestion degree on the DAVL shifts from initial underutilisation toward saturation. Furthermore, using scenario analyses, this study examines a flexible DAVL measure that addresses the tension between rapid AVs development and the necessity of maintaining stable commuting conditions. Insights into the implementation of the DAVL measures are provided, which are expected to be applied in YNC and other urban contexts.