Technologies That Enable Congestion Pricing—A Primer

Functional Processes for Tolling and Congestion Charging

The basic function of any tolling or congestion-pricing system and supporting technologies is to collect payment from users. This can vary significantly depending on particular local conditions; policy framework; strategic, legal, and policy requirements; and the nature of the outcomes that the charging system seeks to achieve. The capabilities and/or limitations of the technologies available have often played a major role in shaping functional design: As the capabilities of technology have increased, the flexibility of tolling and road-user charging can more directly address and improve the key objectives. In the same way that some technology limitations have restricted (and still restrict) some desirable options and functions, the rapidly developing capabilities of new technologies can also offer options that may previously have not been considered.

Whatever system or technology solutions are adopted, the collection of payment from users within the framework of any tolling or road-user pricing scheme must include consideration of the following nine functional requirements:

1. Informing: Providing adequate information to users and potential users (often defined by legislation).
2. Detection: Detecting, and in some cases measuring, each individual instance of use (e.g., vehicle entering a zone).
3. Identification: Identifying the user, vehicle, or in some cases numbered account.
4. Classification: Measuring the vehicle to confirm its class, aligned with the classification framework for the scheme.
5. Verification: Cross-checking processes and secondary means of detection to assist in confirming transactions, reducing processing costs, and providing a backup for potential enforcement.
6. Payment: Pre- and post-use collecting of payment from users based on verified use.
7. Enforcement: Providing the means to identify and prosecute violators and/or pursue violators for payment of charges and/or fines.
8. Exemptions: Providing the facility with the means to manage a range of exemptions and discounts within the context of the scheme.
9. System Reliability and Accuracy: Providing all of the above through cost-effective systems and technologies that can meet the required levels of reliability and accuracy and minimize revenue leakage and fraud.

This base functional framework has been used through several of the following sections of this primer to consider and compare the functional capabilities and operation of candidate technologies and example systems.