Q: Your article on car strobe lights reminded me of a useful study of brake lights I learned about while a student at the University of Michigan — long ago. The combined running/brake lights were least effective; if the following driver was looking away, he had to look back and then decide if the light had become brighter. A high center stop light improved things. Best was three lights: green while cruising, yellow when lifting foot from accelerator, then red with the brakes applied. Hard braking strobed the red. In a line of traffic, a problem ahead would result in a ripple of yellow and red lights moving back the line.
J.W., Naperville, Illinois
A: Were you in college in the 1970s, the disco years? I suspect that such an arrangement may have been distracting, much like the flashing amber party lights we now see on nearly every truck on the road.
