John manages Opus’ research into pavement materials, design and performance. He provides expertise to the New Zealand Transport Agency.

John has over 40 years' experience. His work includes the relationship of deterioration models to pavement design, and modelling pavement maintenance and rehabilitation. He has investigated pavement failures throughout New Zealand and in American Samoa and Malaysia.

John has managed research into pavement materials including hot mix asphalt, granular base course, aggregates, chip seal and bitumen. His technical input for the NZTA includes advice on specifications for granular base course, chip seal and hot mix, and revisions to the pavement design guide and specifications.