is when the control circuit 5 receives the shift signal from the shift control device 4 the control circuit 5 switches the polarities of the wiring of the display segments 2 and background 3 including in the display unit 1 of the indicating instrument 6 thus the currently engaged gear is flashed as shown in fig2 and 4 i e the gear numbers are highlighted the vehicle driver thus receives a visual signal that this is now the best time to shift to the next higher or if applicable lower gear the polarities may also be switched back and forth to make the display unit 1 flash the engaged gear number several times to inform the operator to shift the gear in addition the signals applied to the display segments 2 may be pulse signals from the control circuit 5 further the control circuit 5 may also create a more or less intense flashing of the display unit 1 by adjusting a pulse pause ratio between shifting of the polarities thus the present invention advantageously is able to notify the operator of the vehicle that the time for optimal shifting is approaching by uses long pauses between the flashes of the display unit 1 similarly the operator may be notified that a higher or lower gear should immediately be used by using short pauses between the display unit 1 to provide rapid flashing of the display unit 1 obviously the short and long pulses may be used to provide the.