Presentation: 2025 ND EPSCoR Annual conference 

October 21, 2025, NDSU Memorial Union, Fargo, North Dakota

Integrating Autonomous Vehicles at Rural Interchanges: Operational Readiness and Safety Insights in North Dakota

Rural freeway interchanges present persistent operational and safety challenges, with disproportionate crash risks and congestion compared to urban networks. In North Dakota, where over 96% of lane miles are rural, the introduction of Autonomous Vehicles (AVs) is anticipated to reshape traffic dynamics; however, evidence on their effects in rural contexts remains limited. This study investigates the operational and safety impacts of AV deployment at the I-94/I-29 system interchange in Fargo and four adjacent interchanges. A calibrated microsimulation model is developed in PTV VISSIM, with AVs represented using CoEXist behavioral profiles (cautious, normal, aggressive) at market penetration rates (MPR) of 20%, 40%, 60%, 80%, and 100%. Operational performance is evaluated through Average Speed, Average Delay, Average Number of Stops, and Total Travel Time, analyzed using two-way Analysis of Variance (ANOVA) and Tukey’s Honestly Significant Difference (HSD) test. Automation readiness is assessed through Average Travel Time (ATT) and Average Delay (AD), benchmarked against a 0% (MPR) baseline to determine adoption thresholds. Safety performance is analyzed using the Surrogate Safety Assessment Model (SSAM), applying Time-to-Collision (TTC) and Post-Encroachment Time (PET) to identify conflicts, with focused analysis on merging, diverging, and weaving sections. Extreme Value Analysis (EVA) using the Peaks-Over-Threshold (POT) method and the Generalized Pareto Distribution (GPD) is employed to estimate the probability and return periods of rare, crash-like events. Higher AV penetration is expected to improve safety and reduce delay. Findings will be translated into phase-specific infrastructure and traffic-control recommendations to guide rural AV readiness in North Dakota