This paper explains the design and implementation of a safety system for heavy vehicles. A small-scale embedded system based on Node MicroController Unit (NodeMCU) is proposed and prototyped here. Peripherals such as Global Positioning System (GPS) receiver (for location updates), tilt sensor (for accident detection), gas sensor (for alcohol activity detection), RFID tags and reader (to monitor entry and exit of vehicles in restricted areas), a touch sensor (to indicate an emergency) etc., have been used in this system. A major improvement over existing accident alert systems is that the proposed design makes use of ultrasonic sensors to indicate over-height of the vehicles approaching underpasses (tunnels or rail over road bridges) on highways. A sound alarm is triggered if the vehicle’s height is more than the entry point of the underpass so that the driver can slow down the vehicle. A working prototype of the overall system has been implemented and tested successfully. The data gathered by all sensors is sent to the cloud using the Message Queuing Telemetry Transport (MQTT) protocol and the user can monitor all the updates using his/her android smartphone. © 2020, World Academy of Research in Science and Engineering. All rights reserved.