M. Suhasini, Kommi Jyothi, Koduru Chandra Lekha, Amari Sindhu, Gadde Suhitha 03 04 Urban traffic congestion remains a primary impediment to emergency medical services where critical delays in ambulance transit times directly correlate to increased mortality rates Research indicates that a oneminute reduction in response time can improve patient survival outcomes by 7 to 10 This paper proposes a decentralized Emergency Vehicle Preemption EVP system designed to establish an instantaneous Smart Green Corridor using a heterogeneous microcontroller framework The system architecture utilizes an ESP32 microcontroller at the transmitter TX node integrated within the emergency vehicle and an Arduino Uno at the receiver RX node to manage the Traffic Signal Control TSC logic Wireless communication is established via the Zigbee IEEE 802154 protocol providing a lowpower highreliability data link that operates effectively in highinterference urban environments The TX unit powered by the dualcore processing of the ESP32 transmits roadspecific priority signals which are intercepted by the RX units Arduino Uno Upon signal reception the TSC executes a preemptive interrupt algorithm that overrides the standard fourphase traffic cycle immediately transitioning the requested lane to a Green state while holding conflicting manoeuvres at Red Experimental validation of the prototype demonstrates a significant reduction in the Average Waiting Time AWT for ambulances achieving nearzero delay at signalled intersections By utilizing a costeffective combination of ESP32 and Arduino Uno this research contributes a scalable lowlatency solution for intelligent transportation systems that operates independently of centralized cloud processing or lineofsight dependent infrared sensors Copyright (c) Journal of Science Engineering Technology and Management Science. All rights reserved 2026