Delta-V Lights

Instead of lights that only activate when braking, a delta-v (difference in velocity) light activates in varying colors and intensities, indicating the level of vehicle acceleration or deceleration, deactivating all but a marker light when maintaining velocity, and flashing in the event of lost traction or emergency braking.

For example, a 3 red LED marker light with three circles of LEDs around it, with the LEDs above it amber, and the LEDs below red. Slow acceleration/deceleration would activate the first half-circle of the appropriate colored LEDs, and color-blind individuals could identify them by their position (bottom=red=slowing).