For almost every in-car technology, a time eventually comes when it loses its luster. There are good reasons why cars no longer come with compact cassette players or throttle body injection, it’s because newer, better tech superseded these innovations. While we’re on this train of thought, it’s probably time we admit that head-up displays have some significant limitations, and that they’re probably at the end of their technological shelf lives.
Now, that’s not to say that something has to work well to be cool. The Aston Martin Lagonda’s digital dashboard was famously unreliable, yet it’s still a cool attention-grabber all these decades later. The Vector W8 was a turn-of-the-’90s supercar with a bench seat and an automatic transmission, and two of them broke when Car And Driver tried conducting a road test, but it’s still one of the coolest cars ever made in America.
Head-up displays are cool, having a little readout projected in front of you like you’re piloting a fighter jet is a concept that excites the little part of us that will always be eleven years old. However, in practice, they’ve never quite lived up to their promises of highly legible information with low distraction.
First, let’s talk a little bit about polarized sunglasses. In decades past, they were useful for sport, but also a conspicuous signal of status that attracted a certain stigma. Now though, seemingly every pair of sunglasses is polarized, from fancy wraparound shades to the $2 knockoff Wayfarers near the tills of your local dollar store, and that gives the HUD a significant hurdle. See, when light hits a reflective surface, at least a portion of it tends to become horizontally polarized. Polarized sunglasses filter out horizontally polarized light, and you can probably see where this is going. Since a HUD is normally just light reflected on a windshield, the content displayed dims significantly when viewed through polarized sunglasses, to the point where the information displayed can be hard to read.
But what about night, when only perhaps Corey Hart would be wearing polarized sunglasses? While it’s easy to read a head-up display in those conditions, experience has taught me that many are a little too easy to read. Given how our pupils widen in low light and constrict when it’s bright out, it shouldn’t be terribly surprising that the brightness of a head up display within your line of vision can affect how well you see in the dark, but it’s often helpful to crank down the brightness so you can see where you’re going. Of course, this can also reduce legibility of the information reflected off the windscreen, and the result is always a compromise.
In the past, when gauges were analog and a clear digital readout was nice to have, we could overlook the limitations of head-up displays, but now we’ve kind of evolved beyond them being hugely helpful. I have a new Lincoln Nautilus parked in my driveway right now, and instead of a head-up display, it features two giant screens under one pane of glass stretching from A-pillar to A-pillar, tucked up right at the base of the windshield. It’s a setup that was easy to make fun of when it launched, but now that I’ve lived with it for a few days, I must concede that it’s better than a HUD.
While I wish for more customization options, everything I need from fuel level to speed to navigation maps to what song’s currently playing is seriously close to my line of vision, and nothing washes out when viewed through sunglasses. The screens also dim appropriately at night without losing sharpness, and they have excellent black levels, so it’s not like you’re trying to see through a grey fog.
Plus, it turns out that claims of HUDs minimizing distraction may be standing on shaky ground. Back in 2004, before in-vehicle screens were anywhere near as good as they are now, a group of researchers in Taiwan studied the efficacy of a HUD versus an LCD screen in the middle of the center stack (a head-down display) in commercial vehicle applications. While the sample size is relatively small, as the resulting paper states, “For commercial goods delivery and navigational tasks, the results showed no significant difference between drivers using HUD and HDD, regardless of display arrangement sequence and driving load conditions.”
In a similar vein, a NHTSA-sponsored Virginia Tech study involving a Buick LaCrosse found that drivers spent less time looking at the HUD rather than the gauge cluster when prompted, but more time looking at the HUD than the gauge cluster when simply driving along. As for reaction rate in a simulated emergency scenario, the rate was identical between the HUD and the cluster, while the reaction time was actually a few tenths of a second longer for drivers looking at the HUD.
The head-up display was awesome when it first came to the automotive kingdom, thanks to Nissan in Japan and General Motors in North America, but we’ve reached the point where other technology that overcomes its downsides isn’t just available, it’s already implemented. I wouldn’t be surprised if we see fewer cars with HUDs in the near future, and while I’ll miss their cool factor, even my pre-algorithm nostalgic self must admit that it’s probably time we move on.
Top graphic image: Audi
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Hard disagree. In my M3 and Telluride I get almost all the info I need from the HUDs. Especially the M3’s; it’s amazing.
I keep a pair of non-polarized sunglasses in each car. It’s absolutely worth whatever increased glare I’m theoretically experiencing.
Agree on BMW’s. A speed limit sign and current speed indicator that flashes red when over the limit. Love it.
Thomas has a similarly questionable take on manual transmissions. (Kidding!)
I specifically got my prescription sunglasses without polarization so that the HUD is more visible. In general, I’m a big fan of HUDs. The displays are simple and unobtrusive and in exactly the right place.
I have a 2016 Mercedes Benz C Class that I bought lightly used. It has the HUD. Frankly, I just don’t “see” it anymore. It’s more useful to see that my dash display shows the current speed limit. I don’t think I would pay extra for it unless it came bundled with an options package. Maybe newer versions are more visible.
I strongly disagree, I’ve found most HUDs to be extremely useful as I don’t have to glance down to check my speed – and nothing else really replaces this without at least partially blocking the view of the road.
To address your two main points:
– I don’t wear polarised sunglasses – perhaps they’re somewhat less common where I live.
– I’ve never found HUDs to be too bright at night – pretty much every implementation I’ve used auto dims when the headlights come on.
I really miss having a HUD in our current cars – it’s the number one feature I miss from our Mazda3 that we sold last year.
It’s OK to be wrong sometimes.
I think my HUD with its simple current speed vs speed limit readout is darn near perfect driving UX. I would gladly trade my LCD screen for a handful of useful buttons and a simple HUD.
You can keep your miles of LCD screens, your lane keep assist, your auto-braking….all of it. Just give me some useful button controls and a HUD.
Basically the exact opposite of this take.
“See, when light hits a reflective surface, at least a portion of it tends to become horizontally polarized. Polarized sunglasses filter out horizontally polarized light, and you can probably see where this is going. Since a HUD is normally just light reflected on a windshield, the content displayed dims significantly when viewed through polarized sunglasses, to the point where the information displayed can be hard to read.”
Filtering out horizontally polarized light is a GOOD thing since glare tends to also be light reflecting off an angled surface.
So what’s the solution? How about an embedded backlit LCD display within the windshield like a cheap Timex watch? LCD light is also highly polarized so orient the crystals to take advantage of polarized sunglasses to help increase the readability of the display on a bright day. If an embedded display might be too expensive I’m sure one can be made of thin film and adhered to the glass instead.
Getting a reflection on a glossy surface polarized one way or the other isn’t much of a problem. It will tend to one way or the other, but that can be overcome.
I did that all the time doing product photography in an earlier life. Big polarizing filters on the lights and on the camera. The art director wanted a big reflection on one side of jar and no reflection on the other very well lit side to show the olives in the jar for example.
I think an item on the interior instrumentation and infotainment design checklist should be be “can you see the instrumentation with polarized glasses?” I know for a fact that that Toyota doesn’t consider it.
Getting the the display polarized one way or the other isn’t much of a problem it’s just a matter of how the lcd is assembled.
A thin piece of of Mylar, clear packing tape for instance, will rotate it 90 degrees.
“Getting a reflection on a glossy surface polarized one way or the other isn’t much of a problem. It will tend to one way or the other, but that can be overcome.”
It’s angle and media dependent. IIRC if it hits at Brewster angle for that media the reflected and transmitted light will be effectively separated in polarity. At angles other than Brewsters R&T light will be a mix.
“A thin piece of of Mylar, clear packing tape for instance, will rotate it 90 degrees”
Good idea (if it works) but that would also rotate any transmitted glare. Better to have the LCD cross polarized to that glare from the getgo.
The packing tape is essentially a half wave retarder. Of course different brands and rolls are more or less a half wave thick. I think stress-induced birefringence plays a part in it because it gets stretched in the manufacturing process. I only messed around with it where light is shining through it.
Art school fun.
Also, you can make graffiti or other markings that is only visible when viewed with polarized sunglasses.
I had access to proper 1/4 and 1/2 wave plates so I never tried the tape. Neat idea though.
“Also, you can make graffiti or other markings that is only visible when viewed with polarized sunglasses.”
THEY LIVE!!
(Anyone got some bubblegum? No?)
We had a 2010 Tacoma for a number of years. My polarized, prescription sunglasses totally blanked the LCD radio display. My 2012 BMW convertible has a SatNav screen and an LCD readouts between the gages. I can read both quite clearly with polarized sunglasses, even with the top down and the sun over my shoulder. The screen & gages in the VW don’t wash out with the sunglasses
Yeah, 15 minutes and a checkbox on the spec list and the problem would be fixed. The direction of polarization has to be specified for all the LCD’s components so it’s not random, unless a bunch of random material gets sorted and matched during production which seems unlikely.
I did have an issue with aftermarket windshields causing the HUD to be distorted and very hard to use. With OEM glass, I never had an issue. Too bad I had to fight my insurance company every time to get OEM glass.
They are great, never missed when the mustang was yelling at me because it had a shift light that used a hud windshield
I’m still waiting for CHUD displays. I never know when those little buggers will come scurrying out of their subway tunnels to take me down.
I’ve tried the sunglasses from They Live, but that’s apparently an entirely different species. Not even polarized, which was disappointing.
Well that’s too bad. I’m all out of bubblegum.
Let’s stop all this HUD hate. Basement apartments are an affordable housing option that doesn’t deserve the stigma.
Man, not only is everybody taking Thomas to task on his hot take, many are adding insult to injury by calling out his inexperience with his precious BMWs and Mercedes-Benzes! Rough way to end the day for our correspondent to the north.
Hmmm, 9 comments so far and 8 disagreeing with you, Thomas. Well I’m gonna make that nine out of ten.
The analog gauges in my ’15 Mini are not easy for my old, presbyopic eyes to read, especially when they go into night mode. The HUD projected up onto the little pop-up screen is far clearer and I haven’t noticed any of the issues you cite.
Now I haven’t driven a new Lincoln with the main gauge-screen pushed back towards the windshield, but I suspect it would be similar to my Mini’s HUD, and you may be correct that such solutions cue the swan song for HUDs. Hell, I wouldn’t be surprised if feedback from Lincoln’s geriatric owner base resulted in this particular implementation. The farther the gauges are from my old eyes, the easier it is for me to read them without bifocals.
But until this solution becomes widespread, take your stinking paws of my HUD, you damn dirty ape!
Did a HUD scratch your hand when you were a kid or something? I promise you most HUDs are really nice. Just scratch under the chin or behind the ears.
Fair point on polarized glasses though.
Try driving a new Mercedes-Benz E Class with HUD.
I found it to be phenomenal – leaps and bounds beyond the previous gen E Class HUD – as the new one also includes a small map in the display with highlighted arrow driving directions.
Having it up there means no need to look down at the central display for my directions – and no need to eliminate the more informative gauge display from the driver’s binnacle to get a secondary map display straight ahead.
Meanwhile, BMW is going for 100% HUD across the cabin in their Neue Classe – no screens at all.
So HUDs are here to stay.
The same thing was said about everything going to touch screen a few years ago. Trends don’t live forever.
Well, dials with spinny needles aren’t coming back – Sooo….
Touchscreens are inherently bad design, as are HUDs. Once the “new” wears off and they are no longer the bright shiny object, people will start to gravitate towards what works well. As shown by the fact that physical controls have started to return in places where they were initially eliminated, touchscreens are just a bad solution in cars. Screens can be effective for displaying information if the visuals are designed correctly, rather than relying on designs that prioritize aesthetics.
HUDs are inherently flawed and largely serve as a crutch to compensate for poor interface design.
I love the aesthetics of an old Smiths, VDO, or Veglia instrument set. On the other hand, peeking at the glass cockpit of airbus 320s as I walk by, they seem like a pretty good UI, and aren’t bad looking. Good esthetics, and effective UI are not mutually exclusive. I’m not sold on pictures of mechanical gauges being a better UI however.
I agree. Mechanical gauges aren’t inherently superior. However they are also harder to screw up. I also agree that aesthetics and good human factors are both possible. But in cars, it is rare.
The A320 is a good reference. Cockpits are designed to be used by highly trained people who go through thousands of hours of work to fly those planes. Aesthetically, while the A320 cockpit for sure looks a bit different than the one in a 737 they aren’t aesthetically comfortable or differentiated in a way most people would notice.
Car interiors are used by everyone and need to be immediately useful to a new driver with no training. They also need to provide comfort and differentiation between competitive brands. A grid of text, dials, and charts won’t suffice, whether they are on a screen or mechanical.
You might also notice that those cockpits still use a lot of visuals that mimic old-school dials. A dial works because it provides a lot of information that is easy to read quickly. The position of the needle can be read as distance from zero, and the angle of the needle can also be used to supplement the distance to determine position. Additionally, the rate at which the needle is moving provides valuable information about the context of the position. That isn’t to say they are the best for everything, just that there is real value there that is often lost with digital readouts if they aren’t done well.
Also, HUD on planes are doing something very different. One, they have sky as a background rather than a random collection of stuff on the street. Second, they often provide augmented reality type of information that gains value when seen in context.
True. I can easily read a mechanical watch with no numbers at all. A digital gauge that keeps changing means nothing.
HUDs will not be going away anytime soon. In China, much larger HUDs with AR navigation are trickling down to the half-luxury price point. Additionally, the Xiaomi YU7 has a panoramic HUD like the Lincoln Nautilus’ screen, where the HUD reflects off of the blacked-out bottom of the windshield for better contrast and possibly less eye refocusing. BMW will be copying this idea in their Neue Klasse in the near future, and others may too. You are right that the current tiny HUDs are going away; they will be replaced by bigger ones!
My Mazda3 HUD has none of these issues. What vehicles are you driving with such shitty HUDs? Night driving is excellent, dark polarized lens glasses in AZ sun no problem, not distracting at all. Love it.
Same here. I have several cars with HUDs and they are helpful – I don’t have to check the nav map as often because the info is right in front of me.
Just because your HUD sucks don’t condemn mine!
Same with my CX-50 HUD, and I wear polarized sunglasses nearly every day (because SoCal). It feels weird not to have it on other cars now.
ok what if i like things that suck
I strongly disagree. My 2011 9-5 has a simple, readable HUD that is clearly integrated into the navigation, and I consider it a safety feature. I don’t need to take my eyes off the road, even to check my next turn, and I never really need to look at my gauges. Even better is that it stays on with Saab’s night panel, so the only information I can see is the information I need.
When I drive cars that don’t have a HUD, it feels like something’s missing.
You are a lucky person to have the last of the 9-5s.
Agreed!
Cannot disagree more. The biggest downside to my gradual weaning away from GM cars is that nice, easy to parse things like this are pretty much their domain. I adored the HUD I had on my ATS, and it was a major consideration for why a C5/C6 Corvette kept being so high on my list of what “the next car” was going to be even as I kept choosing other things.
I even really liked the “heads down” display that my Seville had, where it basically had the layout and appearance and functionality of a HUD but Cadillac (for whatever reason) did a 3D projection onto the gauge cluster instead of the windshield.
Hard disagree, HUDs are awesome! I love having the driving direction prompts up in front of me because I hate the voice guidance and always turn it off. Those little visual prompts keep me from missing turns in unfamiliar areas. And I almost never look at the HDD. In fact, one main reason I love the HUD is because invariably, when I get my seat and steering wheel in optimal position, I can’t see the speedometer display in the gauge cluster anyway. I never want to have another car without a HUD, honestly.
I wonder if the tests you refer to would be different today, when more people have become accustomed to a HUD.
You will develop presbyopia some day, and will take all of this back.
The problem with the HUD in cars is no one knew what to do with them. Put speed up, maybe engine info, but nothing too busy or it was just a wash of useless info you ignore while watching the car parked in front of you in stop-and-go traffic.
People wanted AR car vision – a Robocop or Terminator Vision display showing closing speed on cars around you, pointing out wobbly tires or an inattentive driver, or highlighting a cop hiding by a bush with a radar detector with a little flashing target circle and a little pointer flashing RADAR COP 1,499 FT SLOW DOWN SLOW DOWN
Nah, I like seeing key info in my line of sight without looking down at the gauges.
I love my HUD and I find it helps me keep my eyes on the road.