The Problem With IIHS Headlight Testing

Good headlights are a good thing, but is the IIHS letting too much slide?

Justin Hughes

Starting in 2016, the Insurance Institute for Highway Safety began testing headlights and incorporating their performance into the coveted Top Safety Pick ratings. Headlight performance coined Good or Acceptable was required to even be a contender for Top Safety Pick+, the highest rating IIHS awards. Numerous cars lost out on the top rating due to headlight performance alone. While Good or Acceptable headlights used to be enough for the top slot, only cars with Good headlights are eligible in 2018 models. This, plus the addition of a passenger-side small offset frontal crash test, dwindled the Top Safety Pick+ list to just 15.

We can all agree that good headlights are a plus, but there's a big loophole in IIHS's headlight testing methodology. You can read all the precise details of how IIHS tests headlights on its website. These tests incorporate all headlight systems available with a car, but only consider the results of the best system when it comes to overall ratings.

Take for example the 2018 Subaru WRX, one of the few Top Safety Pick+ winners. This is based on a Good rating of the WRX's LED projector headlights with the automatic high beam assist thanks to Subaru's EyeSight driver assist package. EyeSight is a $3,300 package, and while it may appeal to drivers of more everyday cars like the Legacy, Forester, and Outback, the owner of a driver's car like the WRX is less likely to splurge for it. With the loss of automatic high beams, the headlights drop to an Adequate rating, not enough to be a Top Safety+ pick despite the LED headlights.

But wait, there's more. LED headlights only come on the higher trim levels of the WRX. The Base and Premium models have halogen headlights. which earned a Poor rating. So to buy the truly Top Safety Pick+ rated version of the WRX, at the minimum, you need to buy the $31,595 Limited model, plus EyeSight, for $34,895. That's $7,900 more than a bare-bones base model WRX.

Would IIHS grant a Top Safety Pick+ rating to a car where only the top-of-the-line models had to do well on crash tests? I don't think so. Why should headlights be treated any differently? While they may not have a direct effect on life and death in the event of the crash, they're important for an even more critical task: avoiding a crash in the first place. You can't avoid what you can't see.

I can see the argument that requiring exceptional headlights on all trim levels of a car would increase the base price. Even aftermarket LED units for the WRX can run more than $1,000. But IIHS has shown that it's willing to evolve its testing methods to slowly but surely improve the safety of a car. 

Until now there has been no passenger-side small offset frontal crash test. IIHS made this change because manufacturers were designing cars to do well in only a driver-side impact. Under the old rules, there was nothing wrong with that, so IIHS changed the standards to fix the problem. Similarly, while Good or Acceptable headlights were enough for a Top Safety Pick+ rating in the past, only Good headlights qualify this year. 

Perhaps in the future IIHS will change the rules again to require Good or Acceptable headlights across the entire model range to earn their ratings.