This project establishes a vehicle speed limit monitoring system that can operate in both offline and online modes and detect if a car is travelling faster than the posted speed limit on the road it is currently on. The system is especially well-suited for rural or connectivity-limited areas because it is made to be used without a constant internet connection. For real-time comparisons and over speeding alerts, it uses speed limit data taken from Map and integrates a GPS module with a microcontroller.

The system architecture comprises five key modules: real-time GPS tracking, offline map and speed limit storage, location-to-road matching, speed limit comparison, and a driver alert mechanism. A GPS module continuously provides real-time latitude, longitude, and speed data. This data is parsed by the controller and matched against locally stored road segment data extracted and filtered from Map files converted into CSV or SQLite format for efficient offline and online use.

When the system operates offline, it stores data on vehicle speed and syncs this data when it comes online it transmits the penalty points to the concerned persons.

Road ID, speed limit, and start and end coordinates are all included in each road segment record. The closest road segment within a 10–20 metre threshold is found by comparing the current GPS coordinates with these segments using a bounding box filter and then calculating the distance. When a match is found, the system retrieves the relevant speed limit and contrasts it with the vehicle's current speed. A alert sound with in-build display in the vehicle is used to indicate an alert if the speed is exceeded.

This cost-effective and scalable solution is well-suited for integration into embedded systems in two-wheelers, delivery vehicles and transport fleets. By enabling compliance with road speed regulations, the system contributes to improved road safety, fewer speeding violations and the development of smarter transportation infrastructure.