ISO/TS 17444-1:2017 defines metrics for the charging performance of electronic fee collection (EFC) systems in terms of the level of errors associated with charging computation.

ISO/TS 17444-1:2017 is a toolbox standard of metrics. The detailed choice of metrics depends on the application and the respective context.

ISO/TS 17444-1:2017 describes a set of metrics with appropriate definitions, principles and formulations, which together make up a reference framework for the establishment of requirements for EFC systems and their later examination of the charging performance.

The charging performance metrics defined in ISO/TS 17444-1:2017 are intended for use with any Charging Scheme, regardless of its technical underpinnings, system architecture, tariff structure, geographical coverage, or organizational model. They are defined to treat technical details that can be different among technologies and vendors or vary over time as a "black box".

They focus solely on the outcome of the charging process, i.e. the amount charged in relation to a pre-measured or theoretically correct amount, rather than intermediate variables from various components as sensors, such as positioning accuracy, signal range, or optical resolution. This approach ensures comparable results for each metric in all relevant situations.

The metrics are designed to cover the information exchanged on the Front End interface and the interoperability interfaces between Toll Service Providers, Toll Chargers and Road Users as well as on the End-to-End level.