This question applies to a different product than most UX designers are used to discuss: cars.

Long story short, in my short 7 year driving experience I've be mostly driving two cars: a 2005 Peugeot 307 and an E90 2011 Series 3 BMW. For the money they cost, both cars provide excellent value although the far pricier BMW provides far more better driving experience.

When I was young, I rode a crash-without-seatbelt simulator and what I always remember since then is: wear my seatbelt while riding anything with four wheels. Thankfully, for the absent-minded, both cars I mentioned are kind enough to provide visual and audio warning when you start driving without wearing your seatbelt.

The Bavarian BMW's way of reminding you to fasten your seatbelt is a red, always-on icon on the dashboard for the visual part. The audible sound is a one-note, really "warm" and "soothing" and "calm" sound that repeats for... lets say 1 second. No variations in the volume. It just goes "bloom ... bloom" every on second or so. It goes off after some minutes. I think it's also the same sound (different pitch) used by the PDC (parking distance control) system to warn you about an obstacle on the rear while reversing. I can honestly say that sound is engineered in such a way, it almost relaxes me.

The French Peugeot's way also utilizes a visual and an audible notification. The visual sign is pretty much identical with the "Bimmer's", with the difference that: it blinks but after some minutes it goes off (it's always on in the BMW, if you don't fasten your seatbelt). But the sound... oh boy the sound! The sound is a three note, twisted and torturing sound that sounds like a mosquito on steroids that run away from hell itself. It starts low but eventually the volume becomes higher and higher until me or some of the passengers becomes so upset that threatens to damage the car if the sound doesn't stop. It goes like "too-ra-ree too-ra-ree". The sound stops after some minutes, again, if you haven't fasten your seatbelt.

Today, I've observed this pattern I've generated: When driving the BMW for distances no more than 5-10km away (no highways and high speeds) I never fasten my seatbelt despite clearly listening and distinguishing the audio warning. On the other hand, when I drive the Peugeot the moment I hear the screeching sound I almost instinctually reach for it.

So... my question is....Which notification system is considered a success in terms of UX? BMW's where the sound doesn't get on my nerves but I risk ending up dead because of an unfortunate accident (yes it can happen in a low-speed scenario too) or Peugeot's that despite the fact of the sound being unbearable to my ears and calmness, it certainly forces me to always fasten my belt, thus minimizes the possibilities of severe injury.

  • 1
    Only you can answer the question. Which experience do you prefer? Most folks use their seatbelts these days so you're likely the minority user in this case.
    – DA01
    Feb 28, 2012 at 20:04
  • I think this is an interesting discussion but it depends too much on how you define UX. In terms of business goals and annoyance I think it could be more clearly (but obviously) answered.
    – Ben Brocka
    Feb 28, 2012 at 20:45
  • 1
    @DA01 "Most folks.." is a generalization and most generalizations are false. In my country a vast majority of people are dumb enough not to... the percentage is so high, not wearing your seat belt is punished by law.
    – Thanos
    Feb 28, 2012 at 20:48
  • It sounds like the BMW's suffers from a psychological effect called 'habituation'. psychology.about.com/od/hindex/g/def_habituation.htm
    – PhillipW
    Feb 28, 2012 at 21:52
  • "is a generalization and most generalizations are false" = which is also a generalization so therefore it's true but then...SO CONFUSED
    – DA01
    Feb 28, 2012 at 22:31

4 Answers 4


Very interesting question. I suspect that a lot of people will argue that the Peugeot's mechanism is more successful because it causes the driver to perform the intended action more often than the BMW's. I am not sure which truly has a better user experience, partially because i have not heard or seen both systems. This question is somewhat analogous to an alert in a web application. You can alert a user via a JavaScript alert box or by using something a little more pleasant(aesthetically). The alert box is more intrusive and might cause a user to perform the intended action but the intrusion might hurt their overall experience with the application. I am curious to see what others have to say.


The experience is identical if you use the seat belt, but worse in the Peugeot if you don't.

Peugeot is more effective in teaching you to meet a required behaviour, because if you resist then the cost (annoyance) is greater, but the long term (hidden) benefit is greater.

But the user experience I suppose is 'the here and the now', and that just simply depends on your willingness to use seat belts.


It's true that the Peugot's seat belt notification system is more effective in that it results in a higher fastened-rate. However, I'd pick the BMW is a better UX because I don't see the seat-belt fastening as a core-responsibility of the driving experience, but rather a bonus "added-feature."

To translate to the web, it'd be like enlarging the "required" asterisks to the point of distraction and annoyance on a long form (say, a contact page). You'd get less improperly filled out form submissions, but you'd probably bounce so many people away from the page in the process.

Either extreme is poor UX in my opinion.


I suppose it depends on one major variable: does the user get into an accident?

Since the experience only affects those that don't wear seatbelts, we have to assume these are people that don't like to wear seatbelts.

So is the better user experience the one where they are forced to do something they don't want to do (wear the seatbelt) or is it a better user experience to allow them to do what they want (not make the warning so annoying so they can keep the seatbelt off)?

Ultimately, the answer to that is whether or not they get into a serious accident.

Usually the better experience is to guide them so that they don't run into situations where they are forced to do something they don't want to do. However, the consequences aren't usually as severe. But context is everything. Take medical equipment, for instance. This likely needs to have a very obnoxious alarm. That's sacrificing the user experience for the doctor/nurse in exchange for saving a person's life. When it comes to alarm systems, I imagine UX won't always be the primary objective.

  • In the UK wearing a seatbelt is a legal requirement - It's not optional. The interface to work to comply with the law.
    – PhillipW
    Feb 28, 2012 at 21:48
  • The user has to comply with the law...not the device (unless there is also a law requiring seat belt alarms)
    – DA01
    Feb 28, 2012 at 22:29
  • There's an interesting, off topic, car related discussion here, about how much control users should have of vehicles - and how much the technology should control the vehicle. With the amount of tech which goes into new car safety systems its going to become an interesting topic.
    – PhillipW
    Feb 29, 2012 at 10:29
  • I guess the topic question really is "Should the user be able to override warnings in a safety critical situation ?"
    – PhillipW
    Feb 29, 2012 at 10:49

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