Last week, I wrote about the deceptive nature of the VW Tiguan's taillights — specifically, that they have an amber section that isn't used for the turn signal. The post proved much more popular than I'd have guessed, and sparked a lot of interesting debate about the use of amber rear indicators. Let's settle this question.

Here's the fundamental issue: the US (and Canada, but they're just piggybacking on our regs) is the only place in the world where the rear turn indicator may be red, instead of orange/yellow/amber. Up front, indicators need to cast an amber light to differentiate from the white headlamps, but out rear you can actually just use one red-shining bulb for stop/tail/turn functions, as many cars do — especially trucks and jeeps and other vehicles that use off-the-shelf cheap trailer-type lights.



Studies have shown that amber rear indicators are more visible, and as a result, safer. In fact, a 2009 study by the NHTSA found a "statistically significant" accident-reduction for cars using amber rear indicators. Here's the summary:

The principal finding of the report is that amber signals show a 5.3% effectiveness in reducing involvement in two-vehicle crashes where a lead vehicle is rear-struck in the act of turning left, turning right, merging into traffic, changing lanes, or entering/leaving a parking space. The advantage of amber rear turn signals is shown to be statistically significant.

That's just a recent study. Here's a 1977 Volkswagen study that came to essentially the same conclusions.

While there certainly have been plenty of American cars with amber indicators, generally, American car makers seem to prefer all-red (except for the clear reverse light, of course) taillights. And many foreign car makers have red-indicator lights for their US-spec cars, too. Some of the reason may be stylistic — the less colorful lights can look cleaner, in some contexts — and some of the reason may be cheapness — why use two bulbs/LEDs when one set will do?

Personally, I think I prefer amber rear indicators. I kind of like the way they look in a taillight, and I do think they're more instantly identifiable. Usually it's not an issue, but there have been times when a car with a burned-out brake light has looked like it's indicating a turn, for example. Plus, there's lots of ways to have the whole lens look red and have the light shine amber, so why not use a different color?


But I want to hear what all of you think, so I can see what the Jalop consensus is.

So have at it. This is a matter of vital importance.