Operational Analysis and Capacity Improvement Strategies for Signalized Intersections: Case Study on Miami, Florida

The expansion of population and economic activities within urban settings has driven a surge in demand for diverse transportation modes leading to higher traffic volumes, increased probability of congestion due to spillback, and reduced Level of Service (LOS). To reduce that probability, studying signalized intersections is essential as they play a pivotal role in alleviating congestion by reducing delay, increasing traffic flow efficiency, and ensuring safety. This study investigates a congested intersection in Miami, Florida, USA, employing Highway Capacity Software (HCS) to evaluate operational performance. While geographically specific, the methodology is believed to be highly applicable to similar urban settings, where signalized intersections frequently face similar demand-supply mismatches. The analysis revealed severe delays, high queue spillbacks, and a LOS F during peak hours. Two data-driven scenarios were evaluated: (1) optimization of signal timing and (2) integration of a grade-separated pedestrian bridge with signal timing optimization. The combined implementation of the pedestrian bridge and optimized signal timing achieved nearly 53% reduction in delays and improved the intersection’s performance from LOS F to LOS E.