A GPS recording device captures a series of latitude and longitude coordinates over time. As the device is carried by someone moving from place to place, the GPS coordinates record the person's movements. The following map shows a typical GPS recording:
GPS devices are relatively cheap and remarkably accurate, allowing you to record a journey taken on foot, by bicycle, car, or truck. However, by itself, all the GPS device is doing is recording a series of coordinates—the GPS device doesn't know which roads you followed on your journey.
Map matching is the process of taking a GPS recording and matching it against a database of roads to identify which set of roads were used on that journey. For map matching to be successful, you need three things:
An accurate GPS recording of the journey, including enough GPS coordinates to identify which roads were taken.
An accurate database of roads.
A suitable algorithm to match the GPS coordinates against the road database...