This project presents a prototype-based smart traffic light system designed to provide priority passage for emergency vehicles at urban intersections. The system was developed using an Arduino Uno, LED traffic lights, and an HC-SR04 ultrasonic sensor to detect approaching emergency vehicles and automatically change traffic signals.

A model intersection was constructed including a hospital, roads, traffic lights, and toy vehicles. Experiments were conducted under three different traffic conditions: open traffic, moderate traffic, and heavy traffic. Each scenario was tested three times under both normal traffic light operation and smart system operation.

The results showed that the smart traffic light system reduced ambulance travel times in all traffic conditions. The average travel time decreased from 43 seconds to 16 seconds in open traffic, from 52 seconds to 25 seconds in moderate traffic, and from 98 seconds to 48 seconds in heavy traffic. These results demonstrate that emergency vehicle priority systems can significantly reduce delays and improve traffic efficiency.

The proposed system provides a practical prototype for future smart city applications and may contribute to faster emergency response and improved public safety.