Is it possible to do what I'm about to explain?
Make a device that can determine speed using GPS technology. Than get a tri-axle accelerometer. Then build another device that'll record the data given by both to a SD card. Then design a program that defines a coordinate system that defines my house as (0,0,0) with dimensions of 503mi. I then take my 3 part system and take it on a drive around town.
When I'm back at home, I take the collected data from the SD card and run it through the program. The program takes the data and used it to trace a path in the 3D grid. If the starting point (0,0,0) is the same as the end point, the the recorded data is very accurate and the same path can be retraced with a new set of data. However, if the points are way off, then it's back to the drawing board. We'll say that for it to be considered accurate, it has to be accurate up to 1/23mi.