A method and apparatus for reporting a posted speed limit to the driver of a vehicle is disclosed. The position of the vehicle is determined using a GPS receiver or triangulation of cellular telephone signals. The position is used to retrieve speed limit or other information from a database. The information is then reported to the driver. A technique is also disclosed for comparing the actual speed of the vehicle with the posted speed limit and issuing a warning to the driver when the posted speed limit is exceeded.
Intelligent Speed Adaptation (ISA) is an in-vehicle system that uses information on the position of the vehicle in a network in relation to the speed limit in force at that particular location. ISA can support drivers in helping them to comply with the speed limit everywhere in the network. This is an important advantage in comparison to the speed limiters for heavy good vehicles and coaches, which only limit the maximum speed.