Variability investigation of traffic flow characteristics across travel lanes for rural freeways

Abstract Traffic distribution across highways is a critical aspect of traffic analysis and management. Proper and homogenous lane distribution enhances safety and minimizes accidents. This study aimed to investigate lane flow distribution on an Egyptian freeway. The recently constructed Cairo–Banha freeway is 39 km with four travel lanes in each direction. Based on 2022 traffic data, the methodologies employed in this study included analysis and validation of lane flow distribution across both travel directions. The Longitudinal control model (LCM), which incorporates driver behaviors into fundamental traffic diagrams, was then calibrated for the entire freeway and each individual lane. Additionally, comparisons with other studies were conducted in order to contextualize the findings and highlight variations in driver behaviors. Results revealed significant variability in lane flow distribution, as indicated by the traffic flow distributions and speed distributions, as well as the optimal values for flow, density, and speed determined in the study. Unlike the Highway capacity manual (HCM), which generally assumes uniform lane distribution under standard conditions, the Cairo–Banha freeway exhibited nonuniform lane distribution. This variability underscores the need for localized traffic models and microsimulations for improved analyses of traffic distribution. Furthermore, these findings can be utilized to mitigate and manage the unequal traffic distributions of the freeway to enhance its capacity and increase the safety of road users. The first of its kind in Egypt, this study serves as a proof of concept for the application of the LCM to Egyptian roadways, laying the foundation for future studies to refine traffic models and address region-specific traffic dynamics.