Vehicles that are non-roadworthy pose a hazard for all road users and can be one of the main causes of traffic accidents. Previous studies have analysed the impact of the driving style on environmental sustainability and road safety. Starting from this, there was a need to further investigate the relationship between the driving style and vehicle roadworthiness as well. Vehicles that do not comply with the prescribed requirements should be excluded from traffic at a periodic technical inspection. However, the causes of detected vehicle defects cannot be established at a periodic technical inspection. The paper therefore, examines the factors affecting vehicle roadworthiness. First, the failure rate and mileage of vehicles at periodic technical inspection regarding the type of ownership was examined. In addition, a questionnaire was conducted to collect data about the driving style and maintenance habits of different types of car owners. The paper argues that vehicles owned by legal entities were generally in a worse condition than the vehicles owned by natural persons, due to the increased vehicle exploitation, but also due to a more aggressive driving style. Finally, it was found that by modifying their driving style, the drivers can affect the condition of their vehicles, considering the same mileage and maintenance habits.