This part of ISO 17575 defines the format and semantics of the data exchange between a Front End (OBE plus optional proxy) and corresponding Back Ends in autonomous toll schemes. It defines the data elements that are used to generate charge reports containing information about the road usage of a vehicle for certain time intervals, sent from the Front End to the Back End. It also defines the data that can be used to re-configure the ongoing process of gathering charge relevant information in the Front End. The scope is shown in Figure 1.The constitution of the charge report is dependent on configuration data that are assumed to be present in the Front End. The assembly of charge reports can be configured for each individual toll scheme according to local needs. Charge reports generated in accordance with this part of ISO 17575 are consistent with the requirements derived from the architectural concept defined in ISO 17573:2010.The definitions in this part of ISO 17575 comprise— reporting data, i.e. data for transferring road usage data from Front End to Back End, including a response from the Back End towards the Front End,— data for supporting security mechanisms,— contract data, i.e. data for identifying contractually essential entities,— road usage data, i.e. data for reporting the amount of road usage,— account data for managing a payment account,— versioning data, and— compliance checking data, i.e. data imported from ISO 12813:2015, which are required in compliance checking communication.Annex A contains the data type specifications using ASN.1 notation.The protocol implementation conformity statements (PICS) proforma are provided in Annex B.Annex C provides a graphical presentation of the structure of the data elements described in Clause 7.