A comprehensive research has been undertaken to design and develop the GPS based, low cost and easily installable speed limit indicator in public and private vehicles. The device includes the building efficient GPS mapping technique for defining sentinels and a database for sentinel’s storage utilizing minimum memory. These sentinels contain all concerned information required for navigation. Road safety is a crucial issue, ignorance of which can lead to fatalities. These fortuities happen due to speeding which often occurs due to lack of available information about speed limits on particular roads. An algorithm is developed and implemented in C language for simulation purposes by analysing complexities of road structures. Various road tests are performed to illuminate the technical problems in real time. Roads characteristics are examined and different hazards have been optimized through algorithm to resolve problems, faced by drivers. More importantly, it has been implemented within a Field Programmable Gate Array (FGPA), which verifies the simulation result as well.