ROME — From his front-seat perch, Alberto Tomassi, a Roman cabdriver for 50 years, has been both eavesdropper and confessor. He has played impromptu tour guide, thwarted muggings and rushed countless clients to the emergency room.

And he has consoled abandoned wives with a dose of homespun wisdom. “I told one woman whose husband had left her for someone much younger, ‘As we say in Rome, when one pope dies, you make another.’”

Expertly navigating Rome’s narrow, potholed streets — many conceived centuries before the internal combustion engine — he has developed the unflappable calm of a Zen monk.

“If you can get through the first 15 years without getting really angry, you can do it forever,” Mr. Tomassi said. “I just take things as they come.”