Case: Reuven took his neighbor Shimon along with him when driving to Haifa. In the middle of the trip, Reuven fell asleep at the wheel and got into an accident, because of which Shimon was hospitalized for a month and incurred medical expenses. Shimon requested that Reuven pay him for time missed from work (shevet) and medical expenses (ripuy). Reuven does not feel he is responsible to pay, since the damage happened through oness (extenuating circumstances).

Ruling: The Shulchan Aruch (Choshen Mishpat 1:2) rules that nowadays, when we do not have dayanim with authentic semicha, beit din cannot make one who damaged another person bodily pay for depreciation of his value or for pain but can make him pay shevet and ripuy. Although the Rama (ad loc.) cites the Rosh’s opinion that he does not even have to pay shevet and ripuy, since both parties are Sephardi, they are to be held to the Shulchan Aruch’s opinion.
In general, one who directly causes damage to another is obligated to pay even if it happened by accident and even through an oness (Bava Kama 26a). We do accept Tosafot’s opinion that if it was a total oness, then he is exempt (Shulchan Aruch, CM 421:4). However, in this case, it turns out that Reuven had not slept enough the previous night, and halacha recognizes the responsibility of one who has a job that requires concentration to sleep sufficiently the night before (Yerushalmi, D’mai 7:3). Sometimes, one who was negligent but then an unexpected oness happened is not obligated, but in this case, it is not unexpected that someone who is tired will fall asleep at the wheel (the safety authorities warn about it often).
We find that within the laws of watchmen, if one who sleeps and then the object he was watching is lost, it is not considered an oness to exempt a paid watchmen (Shulchan Aruch, CM 303:2). It is the responsibility of such a watchman to stay awake. Certainly, it is the responsibility of a driver to stay awake! There is basis to distinguish between a case where someone went to sleep on purpose and a case like ours where Reuven dozed off accidentally (see Nimukei Yosef to Rif, Bava Metzia 53b). However, since Reuven did not take the necessary steps to avoid it, he should be obligated. Not only did he not sleep enough before the trip, but he should have pulled over to the side of the road when he felt he was getting tired. Thus, he is close to negligence.
Reuven cannot claim that since the accident took place as the car continued while he was sleeping, it should be considered damage through gerama (indirect causality). Many sources in many contexts demonstrate that processes that machines continue after man sets them into motion are considered actions of man (see Har Tzvi, Orach Chayim 134; Chazon Ish, Moed 36).
Among contemporary poskim relating to a driver falling asleep, the Shevet Halevi (VIII, CM 301) says that if they were taking a long trip and the driver fell asleep toward the beginning, he was certainly at fault, but that this is not necessarily true if he fell asleep well into the trip, as even one who is well-rested can become tired. However, it is our belief that there should be culpability in any case because of the ability of a driver to sense his exhaustion and pull over to the side.