Design of a Smart Traffic Light Control System Using Vehicle Density Detection for Urban Intersections in Lagos State

Traffic congestion is a persistent urban challenge in Lagos State, Nigeria, where conventional fixed-cycle traffic signal systems are insufficient to manage the dynamic vehicle density at major intersections. This study presents the design of a smart traffic light control system that employs infrared sensors and a camera-based vehicle detection unit to measure real-time traffic density and adaptively adjust signal timing accordingly. An ATmega328P microcontroller processes density data from four intersection arms and applies a weighted priority algorithm to allocate green-light intervals proportionally. The system was prototyped and tested using a scaled physical model of a typical Lagos intersection, with traffic scenarios simulated across peak and off-peak periods. Results demonstrated a 29 percent reduction in average vehicle waiting time compared to fixed-cycle signal operation under high-density scenarios. The design also integrates an emergency vehicle override module that temporarily clears the path when an ambulance or fire truck signal is detected. Power backup through a battery-inverter system ensures continued operation during the frequent power outages typical of Nigerian urban areas. Field readiness assessments were conducted at the Ojuelegba Road intersection to evaluate sensor placement and environmental resilience. The study recommends integration with broader city-level traffic management infrastructure for maximum benefit. This project establishes a foundational framework for intelligent transport systems applicable across Nigerian metropolitan areas. Keywords: smart traffic control, vehicle density, adaptive signalling, Lagos, traffic management