At national level, a non-representative sub-sample of approximately 1,000 voluntary persons was established in order to test an experimental data collection method via GPS.

These people were equipped with a GPS system for one week, which recorded "GPS traces" during the course of their journeys.

This tracking firstly aims to correct the omission of certain journeys and to provide more accurate information about departure times and transport times.

Secondly, it also provides information that cannot be obtained by traditional methods (very short journeys and terminal routes, waiting times, speed, choice of route, etc.).