An arrangement for metal detection related to a system adapted for electrically driving a vehicle along a roadway. The vehicle is provided with a current collector which is displaceable up and down and sideways in relation to the direction of transportation, in order to be brought into mechanical and electrical contact with elongated tracks positioned below the roadway and comprising a conductor adapted to be supplied with current and put under voltage. The detecting arrangement, comprises one or more coils arranged for sensing the variation of the magnetic field, based on a horizontal and/or vertical distance between the coils and metal parts belonging to the one or more elongated tracks.