Crossroads — Double Set Traffic Lights

This project extends the single crossing into a full crossroads junction with two sets of traffic lights working in opposition. When Road A is green, Road B is red and they never turn green at the same time. Using 6 LEDs, 6 resistors and the same Arduino Uno, this project demonstrates multi-output synchronisation, state management and the logic behind how real junction traffic signals are controlled. It introduces the concept of a state machine , where the system moves through defined phases in sequence which is a fundamental concept in both electronics and software engineering.