What is the blood money (diyah) obligatory upon a Muslim who accidentally causes the death of a Christian in a car accident, and is expiation (kaffarah) also obligatory upon him?

The driver is not liable unless he is negligent. There is no blood money (diyya) for a belligerent (harbi). As for a non-belligerent, whether from the People of the Book or others, there is a difference of opinion regarding them: The Malikis and Hanbalis hold that the blood money for a Dhimmi (protected Christian or Jew) and a Mu'ahid (someone with whom a treaty has been made) is half that of a Muslim, citing the hadith (definition): "The blood money of a disbeliever is half the blood money of a believer." The Hanafis believe that the blood money for a Dhimmi, a protected non-Muslim (kafir musta'min), and a Muslim is equal, based on the general import of Allah's statement: "then blood money must be paid to his family." The Shafi'is hold that the blood money for a Jewish or Christian Dhimmi is one-third that of a Muslim, citing what was narrated from Umar ibn al-Khattab. Ibn Taymiyyah differentiates between intentional killing and accidental killing: for intentional killing, he mandates blood money equal to that of a Muslim, and for accidental killing, half of it. The expiation for killing is also obligatory, which is freeing a believing slave or fasting for two consecutive months. The preponderant opinion is that the blood money for a non-Muslim Dhimmi and a Mu'ahid is half that of a Muslim, as it aligns with the Marfu' hadith (a hadith attributed to the Prophet), and the blood money for a Muslim is one hundred camels or their equivalent value.