The Jemba Inertia Rally Notes System has been developed and proven over just about as many years as we have been competing and is still being enhanced today. It is a tried and tested system that is used at all levels, by individuals, clubs, teams and organisations all over the world. It was originally created by a group of Swedish rally enthusiasts, and it incorporates a high level of sophistication to enhance our recreation.

To create the notes, a sensor box is installed in a standard road car and driven at normal speeds along the open public and private stage route. For safety reasons this is done by two people, one driving and the other adding information, like junction numbers, bridges and landmarks, where they're needed, via a keypad and tablet. The stages are also videoed to allow further detailed desktop checking of the route.

The system is an inertia based system that can be driven at any speed along a piece of road to give a numeric 'short hand' description of the road. These descriptions use corner grades from 1-8, as shown in the graphic. They are further expanded using + or - and words like short long, or very long, plus landscape features, to give as full a description as possible.