Is it obligatory to pay the atonement of fasting for two consecutive months for someone whose father died in a car accident and his blood money (diyya) was paid?

In traffic accidents, the at-fault party bears the blood money (diyya) and expiation (kaffara). The blood money is on his 'aqila (male relatives on the father's side), and the expiation is from his own wealth. This expiation is the freeing of a believing slave, and if one is not found or he is unable to do so, then the heirs must pay it from the inheritance. As for fasting, it is not obligatory for the heirs, because it was not obligatory for the deceased due to his inability to perform it by reason of death.