Lane Departure Warnings, Blind Spot Alerts (Probably) Reducing Crashes: Study

Matt Posky
by Matt Posky
lane departure warnings blind spot alerts probably reducing crashes study

Lane departure alerts and blind spot monitoring systems can significantly reduce crashes if consumers use the features, according to two recent studies by the Insurance Institute for Highway Safety. While this information falls into the no-brainer category, rarely do we get specific metrics on these particular technologies.

“This is the first evidence that lane departure warning is working to prevent crashes of passenger vehicles on U.S. roads,” explained Jessica Cicchino, IIHS vice president for research. “Given the large number of fatal crashes that involve unintentional lane departures, technology aimed at preventing them has the potential to save a lot of lives.”

One reason there isn’t a lot of data on the effectiveness of the technologies is because it’s so difficult to quantify accidents that don’t take place.

Mixing up correlation and causation is a pitfall researchers perpetually have to avoid. The evidence of things not seen is inherently troublesome and the IIHS study may suffer from a bit of the old “magic rock” fallacy. If you’re unfamiliar with the concept, The Simpsons tackled it in 1996 when Lisa alleges the town’s expensive Bear Patrol may have nothing to do with why there are no bears.

However, while we should keep this in mind as we examine the stats, it isn’t meant to undercut the inherent usefulness of lane departure or blind-spot alerts. Some warning is always better than no warning at all when you’re absent minded behind the wheel.

Using previous studies and data from police-reported crashes, the IIHS concluded that systems that warn drivers when they’re beginning to drift out of their lane reduce injuries by 21 percent and total collisions by 11 percent. Cicchino believes the technologies could have prevented nearly 85,000 crashes and 55,000 injuries in 2015, had they been installed on all vehicles at the time.

Similarly, IIHS found blind-spot detection systems cut the chances of lane-changing crash injuries by 23 percent and total accidents by 14 percent. However, a 2015 study of lane departure warnings in U.S. truck fleets found the technology cut the rate of relevant crashes nearly in half, and an analysis by Volvo cars in Sweden found a reduction of relevant injury crashes of 53 percent.

While particularly alert drivers probably have a less-than-dire need for such systems, they are useful. A little light that tells you when a car might be just behind your rear fender is indeed a handy item. Likewise, everyone can benefit from lane departure warnings after a few brain-dull hours spent on the expressway.

Research from the Highway Loss Data Institute backs up the IIHS claims, suggesting the injury rate could be lessened by up to 86 percent. However, the IIHS claims the HLDI hasn’t uncovered direct benefits in the form of lower claim rates from lane departure warnings — primarily because lane departure is typically bundled in with other safety systems that could skew the data.

In the most recent IIHS study, Cicchino included vehicles with optional lane departure warning from six manufacturers: General Motors, Honda, Mazda, Mercedes-Benz, Subaru, and Volvo. Automakers provided information about the presence of optional features on specific vehicles (via vehicle identification numbers) and researchers used 2009 through 2015 crash data from states that provided VINs of the cars involved, making it possible to identify the vehicles and determine if they had lane departure warning systems or not.

You can make up your own mind as to how accurate the estimates are. In the meantime, both institutes feel that implementing the safety features on more vehicles would save lives and significantly reduce accident rates. “Most of these kinds of technologies started out being optional equipment on the highest trim level on the most luxury vehicles. It’s starting to filter down more but it still hasn’t filtered down all the way,” Cicchino said.

Cost is the largest factor, according to a the Alliance of Automobile Manufacturers. “While the industry is proud of these innovations, and eager to see customers embrace these advancements, it’s important that consumers be able to decide how best to spend their safety dollars on these technologies,” an AAM spokesperson said in a statement. “Determining which features are right for their families is a decision best left for consumers.”

[Image: Ford Motor Co.]

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3 of 41 comments
  • Superdessucke Superdessucke on Aug 24, 2017

    How much does this feature normally cost? I have provided the service a few times this year free of charge, by laying on my horn when some idiot starts merging into my lane as I'm passing him. I should send them an invoice.

  • Cirats Cirats on Aug 25, 2017

    Surprising to me how many people on this site appear not to set their mirrors properly so as not to have blind spots. I would expect that from the general population but not on an automobile enthusiast website. On probably 9 out of 10 vehicles (I concede there are exceptions - most of which I would imagine are vehicles with narrow fields of vision out the rear window), if you set your mirrors correctly, there is no blindspot and no need to shoulder check (which is an inherently dangerous activity), and whenever you look over and see that blind spot monitoring light on in the mirror, you'll also be looking at the thing supposedly in your "blind spot."

    • Burgersandbeer Burgersandbeer on Aug 25, 2017

      You might be surprised how many vehicles can have blind spots regardless of what you do with the mirrors. My '03 330i had a left-side blind spot even with the mirror adjusted as far out as it would go. The mirror was too damn small. The problem was caused by North American requirements for "unity magnification" (1:1 reflection with a flat mirror) for the driver side mirror. I replaced it with the euro-market aspherical mirror, dramatically increasing the field of view. The unity magnification requirement is ridiculous to me. I don't see how having to realize an object in the mirror is closer than it appears is more dangerous than not seeing the object at all. Although it's likely true that most drivers don't know how to adjust their mirrors correctly, they aren't guaranteed great results even if they do know.

  • Svenmeier Speedometer display in the center console screen? Why? This is a dealbreaker for me.
  • Alan I do believe that traffic infringements penalties based on income will affect those who are financial able to flout safety regulations.When I drive above the posted speed limit I assess my situation using probability. If I'm confronted with a situation where time is of more value to me than speed I will speed if I assess the probability of a fine to be quite low. I can afford the fine, what I can't afford is the loss of points on my drivers licence.In Australia (12 points in QLD and all States have a point system) we have a points system attached to your drivers licence. An open drivers licence is granted 12 points every 3 years. So, if you receive an infringement for exceeding the speed limit it takes 3 years for the points to be removed. I generally get caught once every 2 years.I think a points system would be a fairer system over a system based on income. Its about retaining your licence and safety, not financial gain by the government.As you can see below it wouldn't take long for many US drivers to lose their drivers licence.[h2]Current penalties for individuals caught speeding[/h2]InfringementPenalty amountDemerit pointsLess than 11km/h over the speed limit$287. 1 pointAt least 11km/h but not more than 20km/h over the speed limit$431. 3 pointsMore than 20km/h but not more than 30km/h over the speed limit$646. 4 pointsMore than 30km/h but not more than 40km/h over the speed limit$1,078. 6 pointsMore than 40km/h over the speed limit$1,653. 8 points and 6 month suspension
  • Wjtinfwb Instead of raising fines, why don't the authorities enforce the laws and write tickets, and have judges enforce the penalty or sentence of a crime. I live across the street from an Elementary School on a 4-lane divided state highway. every morning the cop sits in his car and when someone sails through the School Zone well above the 10 mph limit, he merely hits his siren to get their attention but that's it. I've never, in 5 years, seen them get out of the car and actually stop and driver and confront them about speeding. As a result, no one pays attention and when the School Zone light is not lit, traffic flies by at 50-60 mph in the 45 zone. Almost no enforcement occurs until the inevitable crash, last year some zoned out girl rolled her beater Elantra 3 times. On a dry, straight, 4 lane road with a 45 mph limit. I'm no Angel and have a heavy foot myself. I've received my share of speeding tickets, lots of them when younger. Traffic enforcement in most locales has become a joke these days, jacking prices because someone has a higher income in as asinine as our stupid tax policy and non-existent immigration enforcement.
  • Jeff S If AM went away I would listen to FM but since it is insignificant in the cost to the car and in an emergency broadcast it is good to have. I agree with some of the others its another way to collect money with a subscription. AM is most likely to go away in the future but I will use AM as long as its around.
  • BEPLA I think it's cool the way it is.If I had the money, time and space - I'd buy it, clean it up, and just do enough to get it running properly.Then take it to Cars and Coffee and park it next to all the newer Mustangs.