Must one fast for two months if they hit an elderly person with their car, causing their death, knowing that the driver's speed was 60 km/h, and that the elderly person had poor eyesight and had previously been hit in the same location?

If you cause an accident by doing what is impermissible or by neglecting what is obligatory, and you were able to take precautions, then the blood money (diyya) and expiation (kaffara) are incumbent upon you. However, if there was no transgression or negligence on your part, and you were unable to avoid the accident, then nothing is incumbent upon you.