Is blood money obligatory for someone who hit a person with his car, causing their death, when the deceased was at fault and a Christian, and passersby testified to his error?

If you were unable to avoid the collision with your car, and there was no fault or negligence on your part, then neither compensatory payment (diyya) nor expiation (kaffarah) is incumbent upon you.

However, if you could have avoided the collision but did not, or if there was negligence on your part, then according to the majority of scholars, both the diyya and kaffarah are incumbent upon you. The Malikis and those who agree with them hold that only the diyya is incumbent, without the kaffarah.