Vehicle optical speed indicator - shows speed and braking to driver behind or in front using variable length bar of light

摘要

The indicator shows current vehicle speed as a bar of light whose length is proportional to speed. This bar of light is clearly visible to a driver behind (or one in front or both). (The indicator is mounted outside the vehicle for this purpose). The indicator may be located between the two rear lights and a scale may be provided alongside the indicator. The indicator allows e.g. for the police to see at a glance the vehicle's speed.