Abstract: In order to improve a line arrangement for electrical systems of vehicles, comprising an electrical supply line running from a current feed terminal to a current delivery terminal and having at least one current-carrying inner conductor and at least one protective sheath surrounding the latter in such a way that, when an arc forms, remedial action can be rapidly taken, it is proposed that a detector element which runs along the supply line and is formed in such a way that its electrical and/or optical behavior is irreversibly changed when a local arc originating from the current-carrying inner conductor occurs is provided, and that an isolating circuit which is connected to the current feed terminal and isolates the current-carrying inner conductor from a current source when the electrical and/or optical behavior of the detector element changes is provided.