Impact of Connected and Autonomous Vehicles on the Capacity of a Three-Lane Freeway Work Zone

Abstract: Work zones often face operational challenges like delays, flow breakdowns, and capacity reductions due to bottleneck formation. Connected and Automated Vehicles (CAVs) can offer a potential solution by minimizing delays and adverse effects of bottlenecks while increasing overall capacity within the work zone. However, limited studies have explored CAVs' impact on work zone capacity. Our study aims to quantify their influence across various market penetration rates for work zone in a three-lane freeway segment. We considered two work zone configurations: one lane closure in (1) basic segment and (2) merge segment. Using a microsimulation tool, we developed models for these two work zone configurations on a 1.3-mile segment of California's I-15 NB corridor. Gradually introducing CAVs into simulations from 20% to 100% penetration rates, we observed their impact on work zone capacity, revealing significant trends. For the one lane closure in basic segment, results showed that CAVs can significantly enhance work zone capacity, particularly with increased market penetration rates (MPRs). We observed a non-linear relationship having a positive gradient between CAV penetration and work zone capacity, with significant gains observed beyond 60% MPR and near doubling at 100% MPR. For merge segment, the work zone capacity also increases with CAV penetration, with capacity peaking at lower on-ramp flows. However, this gain can deteriorate at high on-ramp volumes, except in fully CAV environments. Practical tools, such as nomographs, were developed to assist policymakers in optimizing work zone operations and adjusting capacity based on CAV penetration and on-ramp volume.