Is expiation (kaffarah) and blood money (diyah) obligatory for someone who caused the death of a person in a car accident, knowing that he was not speeding and did not see the man in front of him due to another car, and his traffic fault percentage is 25%?

If the person mentioned was the cause of the accident, and it was unavoidable, then there is no guarantee [of financial compensation] and no expiation. However, if the accident could have been avoided but was not due to inattention, then it is considered accidental killing, and the blood money (diyya) is obligatory upon the driver's 'aqila (male relatives on the paternal side), along with the expiation of fasting for two consecutive months if a believing slave is not found [for emancipation].