Is a train driver who transports passengers, some of whom have alcohol with them, sinful, and does he fall under the curse of the Messenger of Allah, peace and blessings be upon him, for those who transport alcohol?

There is no objection to working as a train driver in non-Muslim countries, as the livelihood is permissible, Allah willing, for several reasons: First: The contract is for "driving" not for "carrying forbidden items," and the curse on the carrier of wine does not apply to one who does not intend to carry it. Second: You are not tasked with inspecting luggage, as the transportation is for individuals, and hidden belongings are a secondary, unintended consequence. Third: The forbidden items that some people carry are secondary and not originally intended, and "what is permissible in the secondary is not permissible in the primary." Fourth: Remote pretexts are not to be blocked, and prohibiting the driving of transportation for the sake of what passengers might carry of forbidden items leads to extreme hardship. Fifth: You do not know what passengers are carrying, and without the ability to know, responsibility is lifted. In summary: There is no objection to working as a train driver in non-Muslim countries, unless the contract is for carrying forbidden goods, in which case this specific contract would be forbidden.