The Transport Certification Australia on-board mass feasibility project is testing various on-board mass devices in a range of heavy vehicles (HVs). Extensive field tests of on-board mass (OBM) measurement systems for HVs were conducted during 2008. These tests were of accuracy, robustness and tamper evidence of HV on-board mass telematics. All systems tested showed accuracies within approximately 500 kg of gross combination mass, or approximately 2% of the attendant weighbridge reading. Analysis of the dynamic data also showed encouraging results, and has raised the possibility of using such dynamic information in tamper evidence in two areas. This analysis was to determine if the use of averaged dynamic data could identify potential tampering or incorrect operating procedures, as well as the possibility of dynamic measurements flagging a tamper event by the use of metrics including a tampering index. Technical and business options to detect tamper events will now be developed during implementation of regulatory OBM system application to Australian HVs.