Even if the driver does not interact with the passengers, his chosen speed and the objective probability of an accident will decrease by the number of passengers, whereas both his objective accident loss and his expected objective accident loss will increase. This comes from the fact that the driver is concerned about the safety of the passengers. The more attached he is to his passengers, the greater the changes in the above figures. If the driver talks deliberately to passengers, his time costs ar reduced, whereas his driving skills become poorer. The safety implica- tions are, broadly speaking, like those for radio listening and mobile phone use. If the driver must interact with the passengers or listen to their quarrels against his will, all safety risk components will probably increase due to increasing time costs and poorer driving performance.