Review on Density Based Traffic Signal Control & Emergency Vehicle Detection

Traffic congestion at road intersections can cause unnecessary delays, especially for emergency vehicles. This paper presents a rule-based adaptive traffic signal control system that adjusts signal timing according to vehicle density and provides priority to emergency vehicles. IR sensor modules are used to detect vehicles and determine the density of each lane, while microphone sensors assist in detecting emergency vehicle signals. An Arduino microcontroller processes the sensor inputs and applies predefined decision rules. Under normal or equal-density conditions, the signal operates with 90 seconds red and 40 seconds green. For unequal density, the highest-density lane receives 70 seconds red and 60 seconds green, while the second-highest-density lane receives 80 seconds red and 50 seconds green. When an emergency vehicle is detected, the corresponding lane immediately receives a green signal while other lanes receive red signals. The system aims to improve traffic flow and reduce emergency vehicle delays.