LONDON — Prince Philip was at the wheel?

To the astonishment and alarm of some Britons, he was. At age 97. On a public road, alone. And, on Thursday afternoon, straight into the path of a minivan hurtling down a motorway with a 9-month-old boy inside.

The crash flipped the armor-plated Land Rover driven by Prince Philip. The minivan careened off the road.

Prince Philip and the child were unhurt, though a minivan passenger broke her wrist and the driver suffered knee cuts. The prince told police officers he had been “dazzled by the sun,” a witness said.

Still, some Britons were confused over why the prince, the wizened and gaffe-prone Duke of Edinburgh who is the husband of Queen Elizabeth II, was even driving.