Traffic Control and Pollution Monitoring in Smart Cities Using IoT

Abstract

Urban traffic is developing rapidly and demands quick and efficient control of intersections as well as a simultaneous evaluation of pollution conditions. A prototype of traffic control and pollution monitoring for a four direction intersection using ESP32 is proposed in the study. There are 4 IR sensors that indicate the direction of the vehicle and 4 smoke sensors with pollution related readings for the North, East, South and West approaches. The ESP32 interprets the inputs of the sensors and operates the red, yellow and green signal indicators in a programd order of direction. The green phase duration is 10 s, and may be lengthened to a maximum of 20 s depending on the sensor circumstances. There are 2 s yellow phases that provide transitions between directions. Smoke readings are classed as Normal, Less Harmful or Harmful, based on predetermined levels of less than 700, 700-1199 or 1200 and above. A buzzer is sounded when the smoke reading is 700 or higher. A 16×2 I2C LCD displays local traffic information and sensor information. The ESP32 sends the system status to the remote for monitoring, through the built-in WiFi module and a TCP port on 8080. Experimental realisations of the prototype are shown for signal operation in a direction, pollutant classification, adaptive green-time behaviour, local indication, production of alert and wireless status transmission.