
Modern vehicle headlights temporarily 'blinding drivers' - vanilla-almond
http://www.bbc.co.uk/news/uk-43525525
======
askvictor
Slightly related; I'm finding the bicycle headlights (and to a lesser extent,
rear lights) are becoming a blinding hazard for other cyclists on darker bike
paths. Bike lights have certainly gotten brighter and cheaper over the past
couple of years, and more people have them. Certainly, this is a good thing
for visibility on the roads, where you're competing to be seen against all
manner of light sources, and there is high ambient light. But on a darker off-
road bike path, there is little ambient light, and it completely blinds a
passer by. For a pedestrian, this is an annoyance; for a passing cyclist, this
means you cannot see the path in front of you for a few seconds. I regularly
have to shield my eyes from passing bikes in the evening. I don't think
there's any real solution to this problem; no-one's going to regulate and
police this, and people don't seem give enough cares about (or just don't
think about) anyone other than themselves.

~~~
Tharkun
I cannot understand why a lot of cyclists aim their headlights slightly _up_
instead of _down_. Are they trying to illumunate the sky? The eyes of their
passers-by? I aim mine down, so the road in front of me is illuminated for a
couple of meters.

~~~
nsnick
Cyclists aim their lights up so that cars can see them. The lights on a
bicycle exist more so the cyclist can be seen than for the cyclist to see.

~~~
notacoward
That's what night-vision-friendly _red_ lights are for. If you're using bright
whites so others can see you, you're using the wrong tool for the job and
endangering others in the process.

~~~
Filligree
Nobody expects a red light to be coming _towards_ them.

~~~
setr
Sure you do, in the inverse form of a braking slower car in front of you; its
relatively the same thing either way, direction doesn't really matter. and
when its a sudden change, it _really_ feels like the ahead car is coming to
you

And ofc bike-red lights dont look anything like car red lights, so the
association doesnt really matter outside of teaching, and presumably quickly
picked up even on first-time encounter on the road

~~~
_Wintermute
Don't know where you are, but here it's a legal requirement to have a white
(front) and red (rear) light on a bicycle after dark.

------
beloch
There's a bit of a feedback loop in play here too (i.e. Brightness wars).

If you have dim headlights and are the only driver on the road, your eyes will
adjust and you'll see pretty well. If you pass a driver traveling in the
opposite direction with dim headlights you'll lose a bit of vision for a
little while.

Blindingly bright headlights won't necessarily let you see a lot more than
dimmer headlights and fully adjusted eyes would. However, if you run into
another driver with dim headlights, your eyes won't have to adjust nearly as
much and your vision will recover more quickly. The guy with dim lights is
going to be blind for a while though.

If you want to minimize the time you spend readjusting to your own headlights
after passing oncoming traffic, you want _brighter_ lights than anyone else on
the road. Not just _bright_ , but _brighter_. Thus, there's an incentive for
headlights to just keep getting brighter and brighter as technology enables
this.

Solution? Regulate maximum headlight brightness.

~~~
theluketaylor
In the US maximum headlight brightness is regulated, but the rules and tests
are written extremly poorly. The test is in a specific place at a specific
angle, so there are a ton of headlights that can pass the test, but are far
brighter everywhere else. Obeying the letter of the law while flaunting the
spirit.

To make matters worse, due to the way the rules are written advanced systems
that dim LED headlights specifically in the path of oncoming cars are not
legal in the US. It's becoming common on high end European cars to not just
auto dim but isolate oncoming vehicles from illumination while maintaining
brightness elsewhere.

The key to good regulation here is to write rules about how much light can be
experienced by oncoming vehicles of various height and driver positions and
let engineers figure out how to meet it.

------
BuildTheRobots
Super-Bright headlights are a massive problem - especially as nearly everyone
has their lights adjusted wrong (too high).

Seeing as we're talking about lights on vehicles though, why in the world
isn't the use of PWM dimming on a vehicle illegal?

The first thing you teach kids when programming arduinos is to dim an LED
using PWM and then move the LED through space; oh look, it's not a dim light,
it's a strobing light!

Why in the world it's acceptable to put a strobe light onto a vehicle which by
definition moves though space, is entirely beyond me. If you're stuck either
behind, or worse, watching one go laterally in your peripheral then it's
massively distracting :(

~~~
mkj
PWM is fine. Just needs to be fast enough.

~~~
yeutterg
Yep, usually if you are above 3 kHz or so you are good! Unfortunately, a lot
of today's LEDs PWM just outside the frequency we could detect flicker without
moving, around 100-200 Hz. IEEE 1789 has something to say about this.

~~~
mkj
I don't think 3khz is enough. Say you can scan your eyes 180deg in 0.1s, and
at 3m distance you can discern 1mm features.

If it's 8bit PWM at lowest output (1/256 on-rate) you need about 3(m) x
3.14(pi) / 0.1(s) / 0.001(m) x 256 so you don't see gaps between dots, 24mhz
PWM. That does seem high...

~~~
yeutterg
You're right that it's probably still detectable. But IEEE considers ~3+ kHz
as "no risk." My interpretation is that it could be annoying but unlikely to
cause an accident, etc.

Some of the really good LED dimming solutions I've seen that employ PWM are in
the 30+ kHz range.

Of course, constant current dimming is the best, but it tends to be expensive.

~~~
dognotdog
Dimming by reducing current in LEDs instead of PWM can be very non-linear with
respect to light output, brightness can vary significantly between LEDs being
given the same current (as is typical in a headlamp, with at least 4-8
individual LEDs being driven by a single driver), and temperature dependent,
plus it can cause significant color shift. Long story short, reducing current
for dimming groups of LEDs is largely non-practical.

~~~
yeutterg
Constant current dimming is used widely for mid-power LEDs in architectural
applications. Usually there is a significant number of LEDs, in the 10s or
100s, such that individual variations would average out over the series. You
have some color shift, usually toward greenish hues, but this is generally not
a consideration.

It might be more of a problem in automotive applications, where for a
headlight you use only a few high-power LEDs.

------
numbsafari
Personally I’ve found that the new police lights that use LEDs are the worst.
They’re blindingly bright. So you get to the scene of an accident, or where
there’s some construction work or other hazard and the police are trying to
direct you... except you can’t see a damn thing because of their lights.

~~~
notacoward
I bitched at my town PD about this once. Their new cars have bright white
"takedown lights" that are intended to keep a target from looking at them
directly. I don't think much of the idea in general, but these ones were aimed
so high that they overshot the vehicle being stopped and blinded oncoming
drivers instead. So I emailed the chief. I probably wasn't the only one. In
any case, they both adjusted them more downwards and stopped using them so
much, so it hasn't been a problem since. If you encounter the same problem, I
suggest at least trying to find the right contact to let them know. You might
be surprised by the result.

~~~
yorby
They do something about blinding lights, but not about shooting unarmed
citizens? I'm a bit skeptic...

------
rsp1984
I find this is mostly a problem with SUVs as their lights are naturally
higher.

I nearly always get blinded through my rear mirror when an SUV drives behind
me at night. I can't imagine I'm the only one with this problem and it's hard
to believe that there are no regulations to fix the problem.

~~~
paultopia
Yes, THIS. I often have to hold a hand in front of my rear view mirror to not
be blinded at night by SUV headlights.

~~~
jstanley
You know that little nub sticking out the bottom of the mirror? Flick that and
your mirror will flip to another angle so the lights are no longer pointing at
your face.

Rear view mirrors actually contain 2 mirrors, so when you flick it you get the
same image at the same angle, but only with 10% or so of the light actually
being reflected towards your eyes.

~~~
cannonedhamster
Doesn't work when the high beams are on and tailgating you for going "only" 10
MPH over the speed limit. Also many newer cars are coming out with "auto
dimming" mirrors without the switch but that don't quite seem to cut out as
much light. The problem isn't just with lights either, it's with a lot of
different features including mirrors that can't adequately capture blind spots
and bumpers that cause more harm due to mismatched heights. The differences in
vehicles sizes overall probably lead to quite a few avoidable traffic
fatalities and accidents.

------
mavhc
[https://en.wikipedia.org/wiki/Haitz%27s_law](https://en.wikipedia.org/wiki/Haitz%27s_law)

Every decade, the cost per lumen (unit of useful light emitted) falls by a
factor of 10, and the amount of light generated per LED package increases by a
factor of 20, for a given wavelength (color) of light.

------
aynsof
A real problem I've found in Australia is the overuse of fog lights. People
will drive around the suburbs with four lights blasting from the fronts of
their SUVs. It's widespread, it's dangerous, and it's illegal, but it's
apparently not enforced.

~~~
jazoom
I really don't like super bright LED lights on SUVs. They are at eye height
and very dangerous.

------
jgh
My wife and I moved back to Canada last summer and for a while we were living
in small towns several hours from where our families/the airport/etc are. So I
would, fairly regularly, be making late-night trips through the backroads of
Gray County and it definitely made me a little nervous anytime I passed
someone with bright/incorrectly configured headlights. It is DARK out there
and there are deer and other things that wander onto the road.

~~~
mratzloff
Lasy year I had occasion to drive across western Colorado at night in a
22-foot diesel truck. No lights whatsoever except my headlights and those of
the rare passerby. Pitch black.

When it's that dark, you lose your spatial sense. A single light approached
me, and I realized a motorcycle was driving at me head on. I swerved to avoid
it, and the motorcycle changed direction to continue heading for me. When I
swerved again, it was too much, and the truck began fishtailing and rocking
back and forth laterally. I was sure I was going to tip it. It would have been
an utter disaster, especially since I had no cell service out in the middle of
nowhere.

As I brought it to a stop, it teetered one last time and almost tipped—then
finally, dramatically, landed safely on all wheels.

There was no motorcycle. The lights from the occasional car way off in the
distance had merged together into a single light that appeared brighter, and
therefore closer. The cars weren't even on the same road; as they rode around
a bend the headlights had, in the utter void that I found myself in on these
Colorado backroads, created an optical illusion.

After that night I resolved never to drive in darkness like that again.

------
polskibus
I found that it the worst when the other car is a fairly new SUV. Headlights
are higher than in a regular car. Even if calibrated, straight out of factory,
part of the light is going the wrong direction(ie up)

~~~
sokoloff
Part of the light is _supposed_ to be going up and to the right (for right
hand drive countries) to illuminate road signs that are higher than the light
centerline.

~~~
polskibus
From the right lamp yes, from left much less. I am blinded much more see when
a SUV is driving from the other direction then when it's a standard car.

------
cmrdporcupine
Living rural it's amazing how many urban drivers leave their high beams on the
moment they get on a rural road, not understanding the right protocol for
turning them on and off depending on oncoming traffic, etc. I don't know how
you get through a driver's test like that, but it happens.

That, and it's getting hard to differentiate between high beams and regular
lights on trucks and SUVs. On a dark rural road it can be downright dangerous.

------
Someone
High tech may come to the rescue. Mercedes already sells cars with multi-beam
headlights that try to prevent blinding others ([https://www.mercedes-
benz.com/en/mercedes-benz/innovation/mu...](https://www.mercedes-
benz.com/en/mercedes-benz/innovation/multibeam-led-brings-light-into-the-
darkness/)), and has announced what essentially are powerful DLP video
projectors that would go much farther
([https://www.cnet.com/roadshow/news/mercedes-benz-digital-
lig...](https://www.cnet.com/roadshow/news/mercedes-benz-digital-light-geneva-
auto-show/))

~~~
usrusr
They will use that technology as an excuse with regulators to further increase
brightness on the high setting and then everybody who doesn't get detected
will get their eyes completely toasted. Still beats getting run over by an
Uber, but it will make life hell for everybody who isn't sitting in a car.

On a dark night road, you can already get dangerously blinded even from an
overtaking car with the high beam on (please don't do that, always use the low
beam when approaching humans, from any side), without ever having a direct
sight line to the lights. The technology you are referring to could be awesome
if used with caution, but it will inevitably be used for dazzling regulators
into allowing even brighter headlights, and as an excuse to recklessly running
the high beam all the time.

------
FractalLP
Agreed...it took me awhile to figure out that drivers didn't have their
brights on...they're just that bright. This is dangerous and needs to be
regulated (coming from someone who isn't very pro regulation)

~~~
isostatic
"coming from someone who isn't very pro regulation"

This affects me so it should be regulated. If it doesn't affect me it
shouldn't be regulated.

~~~
briandear
No. It could potentially kill someone so it might ought to be regulated.

Some of the stuff the pro-regulation types want regulated is nonsensically
stupid: in the EU, the shape of cucumbers, the brand names of cheese, the
power output of a tea kettle, the strength of hair dryers — none of those
things have any life or death consequences. People want to regulate internet
content, the height of fences, the width of doorways, the capacity of private
toilets — even if those toilets connect to a septic system and don’t connect
to the sewer mains. Even fucking lightbulbs are subject to the agenda of
unelected officials in Brussels.

People, especially left wing people, just LOVE regulation. They like forcing
by people to abide their opinions on how things ought to be. Considering most
regulation is by executive agencies and not actually written by accountable
elected officials, excessive regulation could be argued as being contrary to
the ideas of a representative republic.

We need less overall regulation, but that doesn’t mean NO regulation.

~~~
cannonedhamster
I can clearly think of very good reasons for most of the things you cited and
a large majority of them have to do with neighbors who don't respect your
privacy rights. For example it's entirely legal in a town near me to burn your
garbage within feet of my house, creating a fire hazard and ash fall on to my
freshly washed car. No legal repercussion because there's no "damage" to my
property aside from the fact that my car is no longer clean, and my house may
burn to the ground, but hey it's their property and regulations wouldn't help
this right? When their habits cause my house to catch fire and they don't have
the money to cover it, you know what would have been nice? Regulations to
prevent this risk to my property.

Hair dryers become a fire hazard above certain temps, same with the tea
kettle. Septic toilets can overflow if not properly sized and done on the
cheap in neighborhoods. Fences fall over, trash in your yard impacts house
values of your neighbors that you can't recoup, width of doorways affects
handicapped access as well as impedes egress during fires. I used to service
homes affected by disasters so I've seen a lot of these first hand because
we're in an area with a lot of houses built before the regulations.
Regulations clearly provide value, especially when protecting property and
safety rights that either are unlikely to be recouped or aren't able to be
effectively proven otherwise.

I absolutely HATE neighborhood associations though. What you're growing in
your front yard, who you have over for guests, what outrageous color you paint
your house, none of that impacts other people nor contributes to overall
safety of others.

~~~
FractalLP
To echo you're trash burning comment....I have a neighbor in a piece of
property adjoining my neighborhood that burns trash and leaves and pine straw
every couple of months. Our entire neighborhood and houses fill up with this
smoke. It causes wheezing fits and I can't walk my dog. Also perfectly legal
in my area.

------
arkades
In the US, at least, there’s also an issue of wider tolerances in headlight
design. When lumens were expensive you’d need tightly focused light cones to
reach regulation-mandated light intensities at given distances. The new LEDs
are cheaper than manufacturing to those tolerances, so...

As a result we not only have brighter lights, but also bigger light cones.

Engineers and businessmen are just doing their jobs. This will only be
corrected by regulatory action.

~~~
usrusr
Even if the beam shapes are perfect: old anti-glare regulations limit the
intensity of light that goes above the horizon and with the technology of the
time that implied a certain limit to below-horizon intensity. Which was still
tolerable when the car hit the occasional bump, peeked over a hilltop and so
on. But with LED and improved mirror designs, we can make the contrast at the
cutoff line much bigger and now technically regulation-adhering cars can be
devastatingly blinding whenever the road surface is not perfectly horizontal.

------
ddingus
So are low duty cycle rear light LEDS.

A constant light appears to be something people compensate for easily. The
spackle of dots left in vision during night traffic, not so much.

~~~
isostatic
I suspect the patterns are there because it forces the driver to be aware
there's a cyclist, rather than yet another Red light.

~~~
ddingus
No. I'm talking about low refresh rate LED lights, not bikes.

Car rear lights.

~~~
isostatic
"low duty cycle rear light LEDS"

You can see my confusion

(low duty) (cycle rear light LEDS)

(low duty cycle) (rear light LEDS)

:D

------
cbanek
This has been a problem for me driving for years. Driving thru non-interstate
highways in the middle of the desert, you're usually restricted to two lane
roads, which have lots of dips and turns which block oncoming visibility.
There are also people passing using the oncoming lane.

At night this can be pretty dangerous, and you can easily be blinded, as many
people run with the brights on and don't notice an oncoming car is there until
too late.

My personal technique for not getting blinded is to watch the yellow line on
the right, lowering my vision and turning it away from the bright headlights
of the oncoming vehicle, while still giving myself enough visual reference to
hold my lane. Once the car passes in a couple of seconds, I can go back to
looking at the road normally. Not looking directly at the headlights helps
return my night vision much more quickly.

------
codebeaker
Maladjusted headlights are worse, my own car has a dial for adjusting
headlight pitch for when towing, and my wife constantly adjusts them "up"
because she can "see better", I think this is also endemic.

~~~
Gustomaximus
Shouldn't towing increase the light angle upwards? So adjustment should only
allow you to drop the headlights from their safe level? Seems a manufacturer
error or lack of regulation that people can choose to angle them past a
standard safe level.

~~~
dariota
There are a number of factors that can affect the beam angle. If you're not
towing and you've only got passengers in the front and nothing in the boot or
in the back, the headlights will point lower than normal and you'll need to
adjust them up.

------
mindvirus
CMU has a really neat research project on programmable automotive headlights
to help solve some of this (and other problems):
[http://www.cs.cmu.edu/~ILIM/projects/IL/smartHeadlight/](http://www.cs.cmu.edu/~ILIM/projects/IL/smartHeadlight/)

If this became commoditized, we could even standardize on invisible markers on
cars to make the problem of identifying where the driver is even easier.

~~~
lulzury
The technology behind this is very cool, but has been out since 2015. For
example, one of their features is that it can illuminate pedestrians crossing
the road. Some searching shows Mercedes is adding this technology to some of
their upcoming cars [1].

I am so excited about tech that can make driving safer.

[1] [https://www.theverge.com/2018/3/6/17086792/mercedes-smart-
di...](https://www.theverge.com/2018/3/6/17086792/mercedes-smart-digital-
headlights-maybach-s-class-cars-daimler)

------
hashkb
Not mentioned is the height issue. My car is pretty low to the ground. A
pickup or large SUV with even 75th percentile brightness, "dipped" is still
directly into my eyes.

So there's the brightness wars, and also an arms race in the height of the
beams.

------
burfog
The lights are too small.

Little pinpoints of light will interact badly with optical flaws in the eye,
particularly for those who have had eye surgery. They also obviously need to
be brighter per area to reach a given level of total brightness.

Large flat panels are best. Note that this does not mean unfocused. A panel
can be an array of tightly packed LEDs that are individually focused, and from
a distance you couldn't tell that there were individual elements. Panels 24x18
inches would greatly reduce the problem of pinpoint brightness.

------
jonhendry18
Lights get brighter, irises narrow letting less light in, so your own
headlights are less effective and you miss details in the shadows. So get
brighter lights. Repeat.

------
tomohawk
Polarized lenses were initially conceived as being for car headlights to
reduce glare, but ended up being used in glasses. Perhaps this should be
looked into again.

Depending on the situation, I wear polarized sun glasses or yellow tinted
glasses at night while driving. The yellow tinted ones work really well to cut
down on the ultra intense and blinding LED lights of police (blue) or work
vehicles (yellow).

------
nielsbot
Definitely true for me. Thought it was because I was getting older, but maybe
headlights have changed too...

------
forgotmypw
Does anyone know if there is any type of glasses that will protect one's
vision against these lights without cutting visibility too much?

I have been seeing this type of headlights more and more often, and it can't
be good.

------
alphabettsy
Poorly aimed headlights and mostly people driving with their high-beams on are
my biggest annoyance.

------
jesusthatsgreat
If self-driving cars are the norm, this problem will disappear over time.. .

~~~
Spooky23
Unlikely. Your per trip cost at peak commuting periods will 10x, so people
will probably adopt more bike and other forms of commuting as long as they can
use the roads.

~~~
emiliobumachar
Maybe. But... maybe not. Per trip costs, including cost of time, already peaks
very sharply at rush hour. Bike adoption is what it is.

------
gwbas1c
We also need to address people who drive with their high beams on at oncoming
traffic.

------
y4mi
i drive a bike to work, in any weather.

the last ~200m of my commute is at the "wrong" side of the road, so the cars
are driving into my direction. I generally drive especially slow there. The
sidewalk is pretty broad and its incredibly rare that even a single person
walks there, but it just want to be careful.

when it rains, i need to dismount from my bike, as i'm unable to see anything
on the sidewalk/cycle lane. seriously dangerous.

