There are many car parks that are either free or use a 'Pay & Display' system and are provided for the public’s convenience. There are no entry or exit barriers to restrict access. It may be necessary to measure the usage of such a facility to ensure that it is providing a good service and that the available space is fully utilised. It may also be necessary to compare the usage with the revenue collected in 'Pay & Display' car parks.

A rural free tourists car park, with a single entrance/exit from the road, needs to be monitored for its daily usage to ensure that it meets the demand of the levels of visitors throughout the season. There are no barriers or variable message signs to control. The data needs to be collected and stored locally for periodic retrieval.