Does a driver's failure to help others who ask for a ride with him constitute a sin?

The basic ruling regarding helping those who need a ride in your car is that it is recommended (mustahabb). It can reach the level of obligatory (wajib) if the person would perish, have their property seized, or their honor violated by your leaving them. The questioner should continue to help Muslims and assist them by giving them rides, for the Prophet, peace and blessings be upon him, said: "Whoever has an excess mount should give it to one who has no mount, and whoever has excess provisions should give them to one who has no provisions." The reward is commensurate with the deed. As for those who behave disrespectfully, the driver is permitted not to give them a ride.