This report is a follow-up on the report "State of the art in monitoring road condition" which was finalised in 2015 (PIARC reference 2016R17EN). The 2015 report summarises the then current state of the art regarding the collection of road condition and road/vehicle interaction data, providing an overview of current practice and emerging technologies. The current report is an update of some chapters due to new findings as a result of recent research. It also discusses technologies in the development and experimental stages.

The document is intended to concisely inform the reader of the range of technologies available, and not to replicate the considerable detail that is available elsewhere for specific technologies.

Each of the road condition and road/vehicle interaction data parameters is discussed, providing a definition of each of these parameters, a description of the measurement methods and the condition/interaction indicators that are derived from the measured data.