By far the most commonly asked question with regard to GPS based speed measurement technology is “How accurate is it?” The difficulty is that there is no single, simple answer to this question, as it depends on many factors. This section presents results from a number of real-world tests to evaluate the performance of various aspects of the SPEEDBOX measurement performance.
None of the results are simulated, neither have they been carried out under idealised conditions, and as such are fully representative of how the system can be expected to perform on a day-to-day basis under “typical” test conditions. The tests were all carried out on a tree lined test track, approximately the same width as a typical two lane highway.
The fundamental physical quantities measured by the SPEEDBOX are acceleration, speed, position and time. Using these quantities, distance, heading and road gradient can also be derived. Each of the quantities is discussed in detail in the links below.