Assessing Performance and Equity of Grade Separators in Heterogeneous Traffic: An Ex-Post Evaluation

This paper presents an ex-post-performance evaluation of four grade separators (flyovers) in Nagpur, India, focusing on equity and efficiency in heterogeneous traffic. Using the moving observer method and six performance indices, the study compares access- controlled (above-grade) and residual (at-grade) link performance during peak hours. The analysis reveals that while flyovers benefit faster motorized traffic, they significantly increase delays and unreliability for at-grade users (including NMTs) by reducing effective carriageway width. The study concludes that flyovers are non-equitable interventions that marginalize slower modes. These results highlight the need for decision-makers in developing economies to rethink urban interventions to ensure benefits are distributed across all transport modes.