A Diploma Thesis titled ‘Investigation of declared and revealed driver behaviour using vehicle diagnostics’ was presented by Natalia Vittoratou in July 2016, with the support and data from OSeven Telematics. The aim of this diploma thesis is the correlation of stated and revealed driver’s behavior with the use of vehicle on-board diagnostics (OBD) data. On that purpose, a large data set from a driving behavior experiment was exploited, which recorded continuously (per second during a period of three months) the behaviour of 17 drivers. These data concerned harsh acceleration and braking, average traffic speed and mileage travelled. Drivers’ stated behaviour was investigated through a corresponding questionnaire. For the data analysis, a mathematical statistical model was developed using linear regression. The results demonstrated a strong correlation between harsh brakings and accelerations on one hand and the number of accidents, the annual income and the declared frequency of harsh braking on the other.