This report describes the work undertaken between 1992 and 1995 under the first and second stages of a research project into road vehicle repair and maintenance costs in relation to road operating conditions. The report first describes the results of a literature review and contacts made with international researchers made in 1992/93. A staged modelling approach was proposed following this review. Potential sources of vehicle repair and maintenance data across six vehicle categories were investigated with respect to the likelihood of obtaining data appropriate to the proposed modelling approaches. Details of the proposed research plan are outlined, giving time scales for the phases of the work. The execution and preliminary analysis of a survey of vehicle fleet operators and a centralised fleet-asset management agency are reported.