VIENNA (AP) — Vienna public transit authorities have found the man who went for a joyride with a Vienna street car. But they still don’t know why.

The Vienna Lines transport authority says the culprit is a former employee who was dismissed some time ago. And police spokeswoman Irina Steirer says the 36-year-old has confessed to nabbing the tram.

But Steirer said Monday the suspect has given no motive other than acting on impulse.

The former trolley driver was apprehended Sunday, a day after unlocking the empty tram’s door while the driver was making a rest-room stop, and then apparently sprinting away once transit officials brought the tram to a halt after less than two stops by turning off the electricity.

The man is not being identified due to Austrian confidentiality laws.