Hide the HUD, say boffins, they're bad for driver safety

It looks likes such an obvious idea: turn car windscreens into head-up displays (HUDs), so drivers don't have to look away from the road to see (for example) the speedometer. Except that it could be a bad idea, because it permanently divides a driver's attention between road and the popup information screens, say researchers …

[Robert Helpmann??]

Move Along. Nothing to See Here.

I looked through the linked article - really just an abstract. If I understand it correctly, it indicates that an unpredictable event will interfere with the performance of an ongoing task. The analogy drawn to using a HUD while driving would seem to be that if something odd or different happens on the road while you are driving, you will most likely be distracted from paying attention to your instrument panel. So far, this seems to be good basic science followed by an odd inference: that a HUD (the primary task) might distract from something out of the ordinary on the road (the secondary task) and not the other way around. Perhaps I am interpreting the article incorrectly, but it is fairly well documented that we really have a fairly narrow amount of bandwidth to use when we focus our attention. If there is something odd going on when we are driving, we are likely to be distracted by it, both for good (e.g. another vehicle swerving near us) and for bad (e.g. a police stop on the opposite side of a divided highway).

[PleebSmash]

simple is better

A car HUD should integrate with mapping and change the color of the road you need to follow, and include gradient color changes like yellow to red to indicate upcoming turns and lane changes.

[Flocke Kroes]

Wrong question

A better question for testing car's HUD is 'How fast are you going?'. If you want the ask 'How many dots on the HUD?', you need to compare reaction times with someone being asked 'How many dots on the instrument panel?'.

[Thorne]

Re: Wrong question

You're quite correct. With the prevalence of roadside tax collectors dressed up as police officers, people need to watch their speedo constantly so which is safer? A HUD or a control panel?

We all know watching the road without distractions is the safest but it's not an option anymore when the government is addicted to the fine revenue.

[Robert Grant]

Re: Wrong question

They're both bad. The only thing I think would work is to have the car know what the speed limit currently is, and to change an environmental colour (one that can be seen in peripheral vision) to red.

[John Brown (no body)]

Re: Wrong question

"have the car know what the speed limit currently is, and to change an environmental colour (one that can be seen in peripheral vision) to red."

Most SatNavs have that functionality already. But the databases have significant holes in them either with incorrect data or no data at all.

[Anonymous Coward]

Re: Wrong question

You're quite correct. With the prevalence of roadside tax collectors dressed up as police officers, people need to watch their speedo constantly so which is safer? A HUD or a control panel?

The answer is cruise control :). When there is a motorway restriction and traffic flow is reasonable (not stop/start), I tend to enable cruise control and blip my speed up and down with its controls. That way, I can spend more time observing traffic and the heightened danger of a road narrowed by construction than on maintaining a speed limit, and the system goes offline as soon as I touch clutch or brakes.

Road safety went IMHO off a cliff after speeding fines were automated via cameras instead of putting people on the road. I'd rather have some people taken off the road for dangerous manoeuvres than for speeding on an empty road at 3am..

[Phil O'Sophical]

Re: Wrong question

Road safety went IMHO off a cliff after speeding fines were automated via cameras instead of putting people on the road.

It's no coincidence that road casualty numbers have recently been increasing in the UK, and are now trending the same way in France just after the French government started installing revenue cameras everywhere.

Maybe some of these university boffins could run a study into that correlation? Methinks the grant money might be hard to find, though.

[juice]

Re: Wrong question

Having just come back from a 2,500 mile drive to Austria and back[*]... I found cruise control to be the best thing since sliced bread. However, the long roads do seem to encourage some bad driving practices on the continent; on the dual carriageways, people tend to overtake with their cruise control set to just a few kph faster than the speed you're driving at. So if you're coming up to a slower-moving vehicle, you either have to brake or rev your engine to nip out before the cruise-controller blocks you in...

Anyhow, back to HUDs, and it's the same as anything else (e.g. smart-phone interfaces): it'll take time

to evolve something which offers relevant information in a non-obtrusive way. Simple shapes/icons, use of colour-coding, etc. The article's point about fighter-plane HUDs is a good one; not only do the military spend lots of money on trying to make the HUDs effective, but the pilots themselves are heavily trained to make best use of them. Something which can't be guaranteed when it comes to Joe Bloggs in his company BMW...

In fact, I suspect the main issue will be that car manufacturers will have to downplay the expectations of people who've seen the heavily contrived VR/HUD displays in things like Minority Report and Iron Man. Slapping something like those onto someone's windscreen is pretty much a guaranteed recipe for disaster...

[*] And the worst bit of this journey? It wasn't the french potholes or the german trucks. It was the M1 and M25, thanks in no small part to the huge swathes of 50mph semi-permanent roadwork zones and the enforced slowdowns for accidents/closed lanes/temporary roadworks. Especially since at least two of the latter proved to not exist at all! And that brings up another point about HUDs and "smart" roadways: information needs to be both relevant and timely...

[Anonymous Coward]

@juice - people passing using cruise control

The "0.5 mph faster than the car he's passing" driver is a big annoyance to be sure, but what is worse at least here in the US are trucks passing trucks. More and more trucks have GPS devices that limit their top speed. Obviously they aren't all calibrated identically, so you can get two trucks that both think they're doing 70 mph but one is slightly faster. It can take 3-4 minutes for one to pass the other, especially if hills are involved which may result in the passer temporarily losing ground if his truck is more heavily loaded and can't maintain speed up a hill.

I just recently completed a 1200 mile round trip and due to this anytime I was approaching two semis traveling close together I increased my speed by at least 5 mph in an attempt to reach them before the one in the back had the opportunity to pull out and begin passing - especially if there is more than one truck in a group! Even worse, if I'm passing in the left lane behind other vehicles I have to stay less than a truck length (about 20 meters give or take) behind the vehicle in front or the truck will take the opportunity to jump in front of me. My response (which I'm not alone in) to this problem is probably not increasing the overall safety of the roads, though I'm sure those who implemented the GPS speed control devices in the trucks feel it is increasing safety.

Can't wait for self-driving vehicles so kids born in 2015 can tell us old fogies how they can't believe people used to manually drive cars, just like kids born in 2000 can't believe we used to only be able to contact our friends when they were at home.

[theModge]

Re: Cruise Control

The answer is cruise control :)

For those lucky bar stewards who have it. I've recently had hire vehicles (vans and cars) that have cruise control and I concur, it's great. It also makes it really obvious that many people don't have it, as they over take you only to drive slower than you \ need over taking until you get alongside when they speed up etc.

Sadly my own car (an elderly focus) lacks this luxury and it'll be staying that way until I finish the PhD....

[Anonymous Coward]

Re: Wrong question

""With the prevalence of roadside tax collectors dressed up as police officers, people need to watch their speedo constantly so which is safer?"

If you feel the need to watch your speedo constantly to know what speed you're doing, you shouldn't be driving a car. Similarly the person who needs a constant reminder of the speed limit.

[Anonymous Coward]

Re: Wrong question

If you feel the need to watch your speedo constantly to know what speed you're doing, you shouldn't be driving a car.

If you're talking about being able to keep your speed within ± 5km/h without looking, say when sitting at 90km/h on a main road, I'd agree. Having been the victim of a camera-generated ticket for doing 51km/h in a 50 km/h zone, though, I'd have to say that that level of accuracy is likely to be beyond even the best of us. Of course I could have just pottered along at 45 to be sure, but the folks behind me wouldn't have appreciated it.

[TRT]

Re: Wrong question

You already know I drive a Prius from another post. One interesting thing I've noted is that at exactly 30mph the electric motor produces a sort of very quiet, pleasant throbbing, mewling noise; like a basket of contented kittens. The pitch changes slightly at about 2mph either side of the cute spot, and disappears altogether at ±5mph. I dislike the 20 zones that have appeared all over London. It's quite hard to stick at 20mph, especially at 5am with an Addison Lee right up your arse.

So, a multimodal feedback system might be more appropriate. Subtle haptic and audible cues combined with an info panel, possibly linked to eye tracking.

[Anonymous Coward]

Re: Wrong question

"Having been the victim of a camera-generated ticket for doing 51km/h in a 50 km/h zone, though, I'd have to say that that level of accuracy is likely to be beyond even the best of us. Of course I could have just pottered along at 45 to be sure, but the folks behind me wouldn't have appreciated it."

Given car speedo's over-egg your speed (it can never report less, and only 10% more, so on average it's always showing more - all due to tyre wear and pressures varying the diameter of your wheels, speedo is calibrated at zero tyre wear, max pressures + a margin), your speedo didn't say 51kmph. And yes, you can just potter along at 45 - it's a limit, not a target.

I'm not some holier than thou driver, I do exactly the same, I just don't moan about it when I'm caught driving faster than I'm supposed to be.

[Anonymous Coward]

Re: Wrong question

your speedo didn't say 51kmph.

Probably not, but the original AC post claimed that good drivers don't need to look at the speedo to know their speed. I don't disagree except that a 2% error should not, in my view, merit points and a fine. Especially when, as you note, the speedo doesn't need to be better than -0/+10% accurate anyway.

[Anonymous Coward]

Re: Wrong question

"Probably not, but the original AC post claimed that good drivers don't need to look at the speedo to know their speed. I don't disagree except that a 2% error should not, in my view, merit points and a fine. Especially when, as you note, the speedo doesn't need to be better than -0/+10% accurate anyway."

No, it said good drivers don't need to *constantly* look at the speedo. 2-3 glances a minute should be enough to catch any casual/unnoticeable drift in speed. But as stated, their speedo probably said 55. Judging by the error and the reference to km/h, this wasn't in the UK (likely it was Australia) and was probably just a fine, not points on a licence.

[Thorne]

Re: Wrong question

"No, it said good drivers don't need to *constantly* look at the speedo. 2-3 glances a minute should be enough to catch any casual/unnoticeable drift in speed"

I wish. There are areas in Australia where the speed limit changes three times within a kilometre. The speed can change on the time of day and change if there is a bus parked beside the road. The police use unmarked cars, mobile cameras and now have legalized wearing camo while hiding in bushes.

You are forever checking your speed and watching for speed sign instead of concentrating on the road. Each year they buy more and more cameras and bombard us with ads that speed cameras saves lives yet tragically each year the road toll increases.

[John Tserkezis]

Re: Wrong question

"Each year they buy more and more cameras and bombard us with ads that speed cameras saves lives yet tragically each year the road toll increases."

To be fair, they've removed many cameras.

Sure, all of them were low-income cameras, but that's just a coincedence - they assure us.

[Thorne]

Re: Wrong question

"To be fair, they've removed many cameras."

Removed? or perhaps just moved? (to a more profitable area)

[Anonymous Coward]

Re: Wrong question

If you feel the need to watch your speedo constantly to know what speed you're doing, you shouldn't be driving a car. Similarly the person who needs a constant reminder of the speed limit.

If you run a small engined car or an eco vehicle, fine, that won't vary much in speed even if you accidentally put your foot down. If you have the kind of car which goes from 0 to "what seems to be the problem, officer" in 7 seconds you have to pay a little bit more attention - hence the use of cruise control.

Personally, I feel a lot safer with some power under the hood as it gives you more options to avoid idiots (this is assuming you don't abuse that power, I have seen that happen too, usually followed by an abrupt attitude adjustment courtesy of a tree).

[John Brown (no body)]

Re: Wrong question

"people need to watch their speedo"

Any reasonably decent driver should have a good "feel" for their speed without constantly watching their speedo. That only become necessary if a driver is treating the speed limit as a target such that the slightest lapse in concentration might mean going over the limit at the "wrong" moment.

[Anonymous Coward]

@John Brown - having a "feel" for your speed

Human beings are unable to properly estimate their speed without using clues like how fast the other cars are going. I'm sure you've noticed when you've been traveling at speed for a while when you reduce your speed you seem to be crawling. About 50-60 miles of my trip was on a state highway in Nebraska in an area with a population density of less than one person per square mile (yes, you read that right) I averaged about 110 mph on that stretch, at the end of which I had to slow down as it entered a town with a speed limit of 35. My brain was so fooled by the change in speed I felt I could have gotten out and walked faster than I was driving. While generally not quite so extreme, everyone has that disorienting sense of slowness when they've traveled at highway speeds for a while and then slow down a lot.

I'd defy anyone to be able to guess their speed within 10 mph if they sit in the passenger seat and travel a stretch of road with no other cars to provide frame of reference, or mile markers, etc. The reason you feel you can is because you do most of your highway travel in a fairly narrow range of speeds. You wouldn't be able to guess it so well if the driver slowly sped up to 100 mph, then dramatically slowed down, then quickly sped up to somewhere in between. You wouldn't know whether he was going 55 or 75 - you'd only be able to infer the speed from other clues.

You might know how fast YOU are going because you typically travel at around the same speed in reference to other traffic, because YOU know the area where you're driving. You have a pretty good idea what the average speed of traffic is in that area, and can guess how much faster/slower based on whether you are passing more often or being passed more often. Put you in an area where people typically drive 15-20 mph over the speed limit, if you don't know that, your guess will be off.

[John Brown (no body)]

Re: @John Brown - having a "feel" for your speed

Although I understand and agree with pretty much everything you say, my point was in reference to "constantly" watching the speedo and as the driver, you have much more feedback than a passenger. You know which gear you are in and you know where the accelerator is. Any sudden change is obvious since the driver caused it. Gradual change can happen but that's why the driver glances at the speedo for a fraction of a second every now and then.

This might feel different in an automatic, which I understand is the norm in the US, but here in the UK a manual gear box is the norm. I've driven an automatic and it does feel very different, but I only had it for one day so not long enough to acclimatise to the new experience.

For reference, I average about 1000 miles per week so my car is my "office". People who drive a few miles to work, then back at the end of the day and barely manage 100 miles per week might not be able to judge things so well.

[Deltics]

Re: Wrong question

That's complete and utter b*llsh*t.

No matter how good your "feel", variations in gradient, proximity of roadside structures (or lack of) and differences in surrounding traffic can drastically alter the perception of speed.

And as for the "it's not a target" horsecrap... it's also not a properly considered, appropriate maximum. It's an arbitrary maximum set decades before the technology and the engineering in modern motor vehicles was even conceived and which takes no account of the variability of conditions or the condition of the vehicle.

If the law is able to ajudge that someone was driving unsafely by dint of the conditions even when under the posted limit, then why can it not also allow that someone is driving perfectly safely even if exceeding that limit at other times of day under other conditions ?

Revenue. That's why.

[Anonymous Coward]

Re: Wrong question

If you want the ask 'How many dots on the HUD?', you need to compare reaction times with someone being asked 'How many dots on the instrument panel?'.

And this illustrates what a crock of shit this "research" is. In the real world we drive with radios on, passengers in cars, satnavs as distractions, the need to look down to check the speedo. What's the point in doing a test so poor it isn't even a simulation, that doesn't counter for real world variables?

I'm sure somebody will already be spewing their lukewarm tea in outrage, because reduction is normally part of the scientific method, to but to posit that an HUD is dangerous when they haven't allowed for the fact that drivers ALREADY spend too much time being distracted by other things in the car is what real scientists would probably term "a load of old cock".

"Boffins" my arse.

[Anonymous Coward]

Re: Wrong question

"In the real world we drive with radios on, passengers in cars, satnavs as distractions, the need to look down to check the speedo"

Yup. It's almost as if these folk picked on a new(ish), idea like HUDs that they could get some publicity by doing some, in my most humble opinion, crappy research on, so they could declare it dangerous and worry Daily Mail readers. Completely ignoring way, way more distracting stuff. If I'm totally honest, thing that distracts me most at this time of year are females wearing summer clothing, in the cool of the evening light. Thinking about it, more than happy to do a research paper on that.

[Stone Fox]

Re: Wrong question

Absolutely. They're also missing the fact that driving is a rules based system and we've all had the rules drilled into us. It's a moving puzzle we're adept at. Psychologically we should be able to incorporate the two much as we do with a satnav;- we can glance at it, instantly read what the symbols mean and incorporate that into the road ahead and our driving strategy. Satnavs haven't caused a huge spike in accidents have they?

All this research has proved is people facing a test they're unfamiliar with in a pressure environment are distracted when the already unfamiliar puzzle changes. As Ledswinger so eloquently said;- "What a load of old cock" ""Boffins" my arse."

[Pookietoo]

Re: Satnavs haven't caused a huge spike in accidents have they?

I suspect it depends where they're mounted - if it's in the middle of the dash, you need to look away from the road, while if it's on top of the dash behind the wheel you hardly look away at all..

[Gene Cash]

These are not boffins

These are trick-cyclist's drinking buddies. Feed 'em to the lions.

[JonW]

Learn from aviation

Having flown with a HUD, KISS is the important thing. If you really need green arrows pointing the way around the car in front, you shouldn't be driving. Reserve it for over speed alerts and other *critical* information - not at all surprised about the findings of this report, tbh

[John Brown (no body)]

Re: Learn from aviation

"If you really need green arrows pointing the way around the car in front, you shouldn't be driving."

Judging by the view out of the windscreen, which is what the driver should be using as the primary information source, I'd say that green arrow in the picture is a turn or lane assist notification. The clue is in the road signs on the gantry. It never even crossed my mind that the car navigation system might be telling the driver when and how to overtake.

[Pascal Monett]

"a pilot is also taught when it's safe to ignore the view outside"

Well that's pretty much any time he's flying above 10,000 feet. There are no trees, deer crossings or sudden turns at that altitude, so he can obviously concentrate on his radar or whatever else needs his eyeball attention. Whatever obstacle is coming his way is another plane, and his radar will "see" it before he does.

On the road, the first rule is Keep Your Eyes On The Road. The second rule is Respect The First Rule.

Jets may be a lot faster than cars, but cars have obstacles all around them at practically all times and one second of inattention can get you to meet one brutally.

Let's remember that the dashboard has two functions : to tell the driver how the car is doing and, if necessary, indicate what is wrong. The driver has enough to deal with what with paying attention to road conditions that can change suddenly without warning. Adding any other data to that information is putting the driver in danger of information overload.

That said, I dearly like the idea of night driving with IR-enhanced HUD display showing me the road as if it were broad daylight. But no arrows or tokens please, just the road as it is.

[Deltics]

Re: "a pilot is also taught when it's safe to ignore the view outside"

When comparing with HUD's in military jets there are some key points to bear in mind:

A pilot is taught.

A pilot is trained.

And of course: A fraction of a percent of the population are deemed fit to even be taught or trained as a pilot (even fewer as pilot of a military aircraft with HUD). Once they have been selected for aptitude the training is then *rigorous* and even then not everyone makes it.

The threshold for obtaining a driving license is, shall we say, somewhat less arduous.

And I have to wonder, why do you "dearly like the idea of night driving with IR-enhanced HUD display showing me the road as if it were broad daylight" ?

So that you can drive along that road in dead of night AS IF it were broad daylight ? Good luck if your HUD glitches, or you happen to encounter a part of the map which isn't quite as accurate or up to date as you might like, while you are merrily tanking along reliant on it to keep you on the grey ribbon.

[Anonymous Coward]

Re: "a pilot is also taught when it's safe to ignore the view outside"

And I have to wonder, why do you "dearly like the idea of night driving with IR-enhanced HUD display showing me the road as if it were broad daylight" ?

So that you can drive along that road in dead of night AS IF it were broad daylight ?

I suspect that will correct itself over time as Darwin gets to work, we initially had the same problem with ABS..

[Phil O'Sophical]

Re: "a pilot is also taught when it's safe to ignore the view outside"

And I have to wonder, why do you "dearly like the idea of night driving with IR-enhanced HUD display showing me the road as if it were broad daylight" ?

Presumably so that one can see obstacles like drunks and unlit cyclists as easily as one can in daylight?

[Muscleguy]

Re: "a pilot is also taught when it's safe to ignore the view outside"

I do wonder about Night IR HUDS, mainly because what happens to the camera when a car with headlights on full comes the other way? How quickly can modern cameras adapt to that? because being presented with a whiteout on the HUD is not going to enhance safety.

[Pascal Monett]

I suppose that infrared cameras are not blinded by visible light, contrary to the so-called night-vision cameras which enhance light.

[TRT]

Nothing at 10,000 feet

until you encounter an Apple iCarHover.

[Nigel 11]

Re: "a pilot is also taught when it's safe to ignore the view outside"

A better simile might be "as if I had been born with brown eyes and was still 20 years old". (I have blue eyes, which are more prone to dazzle than brown ones, and my natural lenses will be less clear than they were in my youth -- give me another forty years and a cataract operation will probably be the least of my worries).

Apart from oncoming drivers who don't dip their xenon-arc lights, my other hatred is the highway designers who think it's sensible to light junctions and roundabouts to near-daylight intensity, leaving the rest of the route unlit. So you lose your night vision passing the junction, and wildlife pays the price. Why not light the whole route to a much lower intensity, say that of a full moon, for which our eyes are well-evolved? Especially now we have LEDS which are a very good match to that requirement. Heck, you could probably run LED lighting off batteries charged from small solar panels, so no expensive copper wiring needed.

[Anonymous Coward]

Re: "a pilot is also taught when it's safe to ignore the view outside"

And I have to wonder, why do you "dearly like the idea of night driving with IR-enhanced HUD display showing me the road as if it were broad daylight" ?

It improves my aim, of course. That's why cars now have automatic screen wipers as well. Duh.

[John Brown (no body)]

Re: "a pilot is also taught when it's safe to ignore the view outside"

"And I have to wonder, why do you "dearly like the idea of night driving with IR-enhanced HUD display showing me the road as if it were broad daylight" ?

So that you can drive along that road in dead of night AS IF it were broad daylight ? Good luck if your HUD glitches, or you happen to encounter a part of the map which isn't quite as accurate or up to date as you might like, while you are merrily tanking along reliant on it to keep you on the grey ribbon."

I suspect he means an overlay on the windscreen from a "night vision" type camera rather than a dynamically mapped virtual reality display.

[Anonymous Coward]

Re: "a pilot is also taught when it's safe to ignore the view outside"

above 10,000 feet. There are no deer crossings or sudden turns at that altitude

Except when it's Xmas, of course.

No, no, he's real alright..

[Zimmer]

M.O.T. ?

Ah, but would the HUD pass the M.O.T. ?

http://www.motuk.co.uk/manual_830.htm

(Icon? Well, they'd fail it for a distracting chip in the glass, wouldn't they? )

[chivo243]

I liked it

I drove my mom's car on vacation, and it has HUD. I was quite nice actually. I found I only had to change my focus when checking side and rear view mirrors. The HUD was low enough on the glass as not to block your view and the color was a cool light blue. I didn't have to count dots or look out for squares. So my attention stayed on the road, and on the HUD when needed.

[Anonymous Coward]

Owner of a Peugeot 3008 with a HUD. Speed is the only thing it displays, so it's not distracting - and the best thing is that I can change the setting to kph at Calais...

Probably now on the 'must, or should have' list when thinking about the next car...

What happened to Skyline, a sat-nav concept from a few years ago?

[Nelbert Noggins]

I had one as a hire car not so long ago, and glancing at the HUD which displayed the speed was less distracting than at the instrument panel. It also integrated with the SatNav and would display up coming turns and distances discretely, mirroring what was displayed in the instrument cluster.

I've had a number of cars which display the turn arrow and distance in the instrument cluster and found them less distracting than having to look at the 'infortainment' touchscreen display.

As for dangerous distractions, the current trend of removing every switch, knob or dial from the interior and replacing them with a shiny touchscreen which turns into a mirror when sun shines on it is far more dangerous than the small discreet HUDs currently in use in cars IMHO. Needing to increase/decrease the AC temperature by prodding around on a touchscreen instead of just turning a dial while still looking ahead at the road is not a step forward in driving safety.

[Arachnoid]

Re Bad exmaple

Yes in that something that is not familiar needs more use of section of the brain used for learning which is slower and ergo more time to resolve the problem.Whereas an experienced driver looking at something familiar like the speed displayed be it via dial or on a heads up display uses preconfigured brain cells in a different part of the brain which do not tax the individual as much.

[Mark 85]

A programmable HUD maybe...

I'd like one that I can set the info that I want... speed, engine/tire(tyre) alerts, maybe mpg for long road trips.

Oh.. and I want a selectable option for the machineguns and missile launcher to take care of distractions such as idiots and that guy with the 10,000 Watt speaker system that makes my car shake to his music from 50 yards away and hangs on my bumper even at 10mph over the limit but won't go around even if I slow down to 10 under the limit. I guess I don't want much, do I?

[Nelbert Noggins]

Re: A programmable HUD maybe...

Maybe you need to chat to Volvo and ask them to add a HUD. They've used TFT's for a few years now instead of fixed instrument displays and allow different display configurations on the screen.

Probably find some health and safety issue prevents the machinegun/missile launcher option... someone might burn themselves on a hot gun barrel or some such excuse, if you leave the car in a car park too soon after firing...

[R Callan]

DOHH

How can anything be "slowed down (judgement) by “as much as 200 per cent”." If it is slowed down 100% it is stopped totally, completely, absolutely. Anything which makes rediculous statements should be ignorred until the authors learn a language, any language. The fact that HUDs are probably a serious distraction makes the mad claims detract from the important message.

[John Brown (no body)]

Re: DOHH

"How can anything be "slowed down (judgement) by “as much as 200 per cent”.

Maybe it was an Italian tank. One forward gear and 6 reverse. You need to picture the graph plot of velocity with a negative axis.

[Securitymoose]

Simple answer

Abolish speed limits universally. No need to look at the dash at all then. Save a fortune in hardware and police too, so that they can get on with catching criminals. Yes, I hear you safety campainers - people killed and all that jazz, but do we really need the nanny state telling us not to kill ourselves? Control speed with road humps, pedestrian safety barriers and chicanes in urban areas and forget it out in the country or the motorways where pedestrians are limited and shouldn't be wandering around like dopey bozos. No need for HUD or anything then, other than a light to tell you when to top up with fuel.