Cliff Nicholls was until recently a Principal Research Scientist and Senior Academy Fellow at the Transport Research Laboratory. He is, or has been, a Fellow or Member of five professional institutions and a liveryman of the Worshipful Company of Paviors.

He was also the convenor of the Comité Européen de Normalisation task group responsible for test methods for asphalt mixtures from 2000 until 2015. He is author of Asphalt Mixture Specification and Testing, and the editor of Asphalt Surfacings, also published by Taylor & Francis.

Arthur Hannah has held senior management positions in the asphalt industry over 45 years, with considerable experience in site inspections and the resolution of problems in the asphalt production, surfacing and quarrying industries, and in setting up quality management systems. He recently completed a term as President of the Institute of Asphalt Technology.