Third Brake Light, Tested & Confirmed

Jalopnik recently wrote about the surprisingly structured, rational addition of the third brake light that's been mandatory since 1986. Psychologist John Voevodsky came up with the idea for a third light that's only on when braking, as opposed to tail lights which are always on at night and just brighten when braking. From there it was a well-controlled scientific experiment, randomly applying the feature to taxis and comparing accident rates. The results: "The light prevented 5.4 collisions, 1.02 cab driver injuries, and $643 of taxicab damage per million miles." Now that's good design!
[via Jalopnik]


Just Another Abused Air Traveler said...

Sounds good. But at what cost? And what savings?

Dave Gustafson said...

That's a good point - the savings are quantified, but not the cost. A quick back-of-napkin calculation: assume a car has a useful life of 100k miles. Since we save $642 per 1M miles, that's $64.20 of savings per manufactured third light - and I'm willing to bet the full cost of each produced rear light is under $20. And that's just in damage to one car; I don't think that includes the other car, or any injuries. So yep, I think it's win-win!