Is blood money (Diyya) or expiation (Kaffarah) obligatory for someone who accidentally caused the death of his friend in a car accident, knowing that he was not directly responsible for the accident?

In traffic accidents, blood money (Diyah) and expiation (Kaffarah (definition)) are obligatory upon the driver alone if he is at fault, and his 'Aqilah (male relatives on the father's side) shall bear the blood money on his behalf. However, if the fault is shared between the driver and another party, then blood money is obligatory upon each one at fault, proportional to his error, and expiation is binding upon both of them. If the driver has no share of the fault, then neither blood money nor expiation is binding upon him. The driver is exempted from liability if the accident was due to an act of God (force majeure), a significant action by the injured party, or the fault of a third party. In the event that the driver and the injured party both contributed to causing the damage, each bears the consequences for what was lost by the other. If the direct perpetrator and the indirect cause combine, then responsibility lies with the direct perpetrator, unless the indirect cause was a transgressor and the direct perpetrator was not. If two causes contributing to the damage combine, then each cause bears responsibility according to the proportion of its influence. The identification of the at-fault party and the proportion of fault is determined by the competent authorities.