This paper explains the design and implementation of an on-demand vehicle tracking and alcohol activity detection system using microcontroller and suitable peripherals. Correct information about a vehicle’s location is extremely important in managing fleet, logistics and cab services. Unfortunately, operators or owners of such services find a tough time to perfectly spot their trucks or vehicles owing to irresponsible, reluctant, untruthful and unlawful drivers. We propose a system based on Global System for Mobile Communication (GSM), Global Positioning System (GPS), PIC microcontroller, alcohol sensor etc., which can provide the whereabouts of the vehicle in the form of an SMS to the owner’s mobile phone. A working prototype of the proposed system was created and tested successfully. Such systems will be of great utility to cab and fleet operators in developing countries such as India etc.