alt.hn

7/17/2026 at 8:12:59 PM

Painting the sides of railroad rails white to reduce derailment

 https://www.up.com/news/safety/Tracking-Rail-Heat-260608

by zdw

7/17/2026 at 11:22:46 PM

In a somewhat related practice, some roads in the Tour de France this year have been painted with "white shit" (rider Tom Pidcock's words) in order to combat the asphalt melting in the heat, with the unfortunate side-effect that it seems to be slippery and several riders (including Tom Pidcock) crashed going around a corner when the lost traction.

Coverage here: https://velo.outsideonline.com/road/road-racing/tour-de-fran...

But of course, this was done in response to past serious crashes that occured because the asphalt melted. So, it's sort of a damned if you do damned if you dont scenario for the organizers.

by atourgates

7/17/2026 at 11:48:55 PM

Pepe's Towing in Los Angeles reports asphalt collapses where loaded semitrailers are parked with the landing gear down. On hot days the concentrated load of the landing gear sometimes punches through the asphalt.[1]

This is why truck dock areas are usually paved with concrete.

[1] https://www.youtube.com/watch?v=LBrULmCGJfc

by Animats

7/18/2026 at 2:31:20 AM

Years ago Chicago started putting concrete pads on the road at bus stops because the busses stopping in the exact same spot repeatedly was carving ruts into the asphalt.

by jordanb

7/18/2026 at 4:43:38 AM

A city I used to live in did the same thing when they refurbished all the major bus stops. I always wondered why

by superb_dev

7/18/2026 at 4:48:11 AM

Also if a vehicle is stopped and the driver turns the wheel (with power steering this isn't hard) - it will eventually drill holes in asphalt - you can sometimes see this in house driveways where someone turns around.

by bombcar

7/18/2026 at 12:32:18 PM

You can even see the asphalt "waves" pushed by the buses stopping here over and over again

by toasty228

7/18/2026 at 4:08:07 AM

Yeah, my city is currently going through every bus stop in the city, redoing the pavement in concrete. Construction season has been nasty for us this year :p

by cwillu

7/18/2026 at 1:27:35 AM

Motorcycle riders also report their sidestands sinking into asphalt on very hot days, to the extent that many of them carry some kind of wide weight-spreading thing to put under the stand. Apparently a face plate (?) for an electrical junction box works great.

by andrewflnr

7/18/2026 at 2:30:31 AM

Usually, a crushed soda can is good enough to prevent the kickstand to sync in the pavement. You can usually find a can in a random parking lot. That, or find a strip of concrete. That's why sometimes motorcycle park on the sidewalk in front of big box stores on a hot day.

by pacbard

7/18/2026 at 3:23:41 AM

Yep, I use a soda can and have never had any issues.

by MrMember

7/18/2026 at 3:42:39 AM

My bicycle did this as kid in the summer

by esseph

7/18/2026 at 10:52:01 AM

This isn't a new thing in the Tour and it is normally not a problem, but since someone crashed on it then it must be the "white shit" that caused it. Not one of the hundreds of other variables - like the rider.

by Dah00n

7/20/2026 at 5:25:27 PM

Several riders independently crashed in the exact same spot, including Pidcock who is a famously good descender.

These are literally world class professionals at riding their bikes downhill around corners without crashing. If they say the white shit caused the roads to behave differently than they expected, I'm going to believe them.

by atourgates

7/18/2026 at 4:28:50 PM

Paint is usually slippery. There are special standards for how slippery a paint painted on the tarmac can be. But it’s calculated for cars, not racing bicycles with teeny-weeny tires. Could have been easily the paint.

by throw1234567891

7/19/2026 at 7:07:16 AM

Perhaps they should have used some type of traction paint.

by NetMageSCW

7/19/2026 at 10:22:54 PM

There are other problems with that in wet conditions.

by throw1234567891

7/18/2026 at 5:41:50 PM

I mean, one of the first things they teach in motorcycle safety classes is that the road stripes are slippery and could cause a crash, especially in the rain. Even if there us a standard for how slippery it can be, it still doesn't match the traction of the road surface.

by olyjohn

7/18/2026 at 5:04:56 AM

> But of course, this was done in response to past serious crashes that occurred because the asphalt melted. So, it's sort of a damned if you do damned if you don't scenario for the organizers.

Well, not entirely. You always have the option of repaving the roads with cobblestone or something.

by thaumasiotes

7/19/2026 at 11:02:37 PM

Cobblestones?

They're very slippery when dirty or wet. Seems like a much worse option.

by subscribed

7/18/2026 at 8:44:18 AM

Or just have the cyclists use fatter tyres.

by albumen

7/18/2026 at 9:56:36 AM

That would also require fatter wheels. Which together have higher moment of inertia which makes for slower bikes (as more energy is required to get the wheels to the same speed).

Not exactly what people want in a race.

by dgoldstein0

7/18/2026 at 11:48:58 AM

You can buy faster bikes than what is allowed at the Tour, so the only concern would be making records incomparable.

by adrianN

7/18/2026 at 10:48:21 AM

And yet fatter tyres are faster than the slimmer ones they used to run. No-one run slim tyres these days.

by Dah00n

7/18/2026 at 10:13:09 PM

I could be wrong, but it turns out that somewhat fatter tires with lower pressure are faster because less energy is wasted by deforming slightly and rolling over small bumps, as opposed to thin high-pressure tire "bouncing" over pavement. There is less wasted vertical motion with the wider tires.

by webnrrd2k

7/18/2026 at 10:59:27 AM

Fatter wheel is better than a dnf right?

by baq

7/18/2026 at 4:29:35 PM

Not really. If you finish second, you are the first to lose.

by throw1234567891

7/18/2026 at 9:16:24 PM

...I know absolutely nothing about competitive cycling, but it occurs to me:

1. Would the Tour de France have been rescheduled if it was raining that day?

2. If the answer to #1 is no, is the paint any more slippery than water would have been?

3. If the answer to #1 is yes, then they should also reschedule for extreme heat.

by Wowfunhappy

7/20/2026 at 5:27:54 PM

1. No, they ride in the rain all the time.

2. It's not so much that the white shit (actually lime) is slippery, it's that it's unexpectedly slippery. Riders are generally quite good at going the right speed for the conditions. This just a new and unexpected condition they don't have experience with yet.

3. They did shorten one stage because of extreme heat, and there has been talk about rescheduling (both in terms of season, and moving the races into cooler parts fo the day), but the Tour is pretty tradition bound, so it'd take something quite exceptional to see that happen.

by atourgates

7/18/2026 at 12:41:07 AM

At least they're doing something.

I couldn't believe the state of US railtrack:

https://www.youtube.com/watch?v=9X2A2f6E5DI

Just go slower! We don't want to pay for maintenance. What's the worst that could happen? You derail and your toxic payload catches fire and poisons the neighbourhood?

https://en.wikipedia.org/wiki/East_Palestine,_Ohio,_train_de...

by amiga386

7/18/2026 at 12:44:23 AM

Maintenance is expensive, profits are now!

by pixl97

7/18/2026 at 5:22:59 PM

A new mantra for Wall Street.

by euroderf

7/18/2026 at 4:10:56 AM

I hate that you are both correct.

by edoceo

7/18/2026 at 4:35:42 AM

It's funny you mention that, since I mentally associate Union Pacific with the worst of US rail disinvestment. They're the ones that were patient zero for the "precision scheduled railroading" brainworm that led all our railroads to downgrade track and lengthen trains to insane lengths[1]. Or at the very least, they were at the top of Amtrak's delay-shaming list until a few years ago[0] when they somehow improved???

...anyway, I'm now genuinely wondering how the hell rail in such an awful state can still maintain the correct gauge for trains to run on!?

[0] https://www.amtrak.com/content/dam/projects/dotcom/english/p...

[1] Salt Lake City is trisected by Union Pacific freight rail. We have some of the largest city blocks in North America, but they're still not long enough to avoid a single stopped Union Pacific train blocking multiple crossings for hours on end. If you want to really, REALLY hate trains, move to the west side of SLC.

Also, talk to your politician about the Rio Grande Plan.

by kmeisthax

7/18/2026 at 6:32:11 AM

This of course beeing the effect of seemlessly welded together rail with nowhere to go..

by warumdarum

7/18/2026 at 10:15:25 AM

Indeed. Didn't they used to have expansion gaps?

by jimnotgym

7/18/2026 at 11:15:17 AM

They did. It's what caused the click-clack sound trains used to have, and the change to continuous welded rail is why there is no click-clack anymore.

by cgyvbunji

7/17/2026 at 11:57:28 PM

I love a simple solution to billion dollar problems

by kylehotchkiss

7/18/2026 at 11:20:59 AM

...that will be done for a few years, dwindling quality and measurement, lack of continuous data collection, or sparse, which loses 'track' of performance and effect. Then, lots of subcontractors will use the wrong paint (maybe a black market appears), incorrect application, too thick too thin on top instead of the sides... more derailments start occuring because the whole program gets used to boost stock price and try to get fed contracts instead of actually engineering a solution and maintaining it as protocol.

Lots of major industrial specialty paint manufacturers and white labelers are publicly traded, owned by BR & VG.

by conorcleary

7/18/2026 at 9:53:29 AM

I'm surprised that this is as effective as the numbers suggest. I would have thought steel rails would be pretty good at reflecting/radiating heat. TIL.

by elric

7/18/2026 at 2:18:48 PM

Reflecting and radiating heat are mutually exclusive, and if some material is good at radiating heat, it is also good at absorbing heat, otherwise it would violate the laws of thermodynamics.

It is a bit more complicated than that because light come in different wavelength, but it is the general idea.

Railroad rails tend to be dark except for the polished top surface, so they absorb/radiate the heat more than they reflect it. Painting them white changes that, it makes them less effective at radiating their own heat, but because they don't produce much heat by themselves, it is not a big effect, but it also makes them less effective at absorbing the heat from the sun, a much greater effect, so, the rails get cooler overall.

by GuB-42

7/18/2026 at 1:43:09 AM

"That’s huge. If you’re not fighting the sun’s heat, you dramatically reduce the risk of the rail shifting.”

Am I misreading or does this say the opposite of what they meant?

by tiagod

7/18/2026 at 2:06:22 AM

I think the safety officer meant that white paint prevents the rail from heating up. The heating of rails contributes to problems with derailment. If the heat isn't a contributor, that heat is one less thing you have to fight (as in account for).

But the photo caption paraphrases him and says that the white paint fights (as in prevents) the heat, which uses similar words but a different logic to it (but the same overall meaning).

If I've got that right, then I think the blame lies on whoever wrote this article for making it confusing.

by adrianmonk

7/18/2026 at 10:24:38 PM

Reflecting the sun means the rail no longer has to fight the sun's heat.

Without the paint, the sun heats the rail and heat expansion fights against the elements holding the rail in place until the rail cools down or something moves. If the something moves, trains can derail.

by toast0

7/18/2026 at 1:47:31 AM

You are misreading. Basically the white paint is "fighting the sun's heat".

by earth-tattoo

7/18/2026 at 8:23:13 AM

But that's backwards. I took it to mean the rails or the engineers are no longer fighting (coping with) heat input from the sun because the rail never receives that heat when it's reflected away by the paint.

by foxglacier

7/18/2026 at 11:17:38 AM

It means the paint is fighting the energy conversion potential encroaching on the steel, in place of the steel fighting it with no covering or shield

by conorcleary

7/19/2026 at 11:35:42 PM

I know what it means. "you're not fighting the sun's heat" means "the paint is fighting the sun's heat" but that's no explanation of how it could mean that. I say it's backwards because clearly whatever's doing the fighting is not the paint because it has the opposite effect. It must be the steel, as you say, or the people struggling with the problem.

by foxglacier

7/18/2026 at 11:16:48 AM

Fighting like a verb I think

by conorcleary

7/18/2026 at 6:07:55 AM

> “When people first saw it, they said, ‘Why haven’t we been doing this for a hundred years?’” Doerr said. “That’s the kind of question I love to hear, because it means the culture of safety innovation is alive and well.”

Union Pacific haven’t been doing this precisely because they don’t have a culture of innovation…

by DaiPlusPlus

7/18/2026 at 3:39:40 PM

The question applies more broadly than Union Pacific. Why hasn't this been an industry standard for 100 years?

by mark-r

7/19/2026 at 7:15:28 PM

> Why hasn't this been an industry standard for 100 years?

Because the US heavy rail system is a duopoly with no incentive to innovate.

by DaiPlusPlus

7/18/2026 at 5:10:53 PM

According to the Dutch railway maintainer, it's not needed there, and the effect is not really proven: https://www.prorail.nl/veelgestelde-vragen/zomer/waarom-zijn...

Same for the Swiss, according to the natioanl railway company the results of their tests were “inconclusive”, but other operators of the Swiss network say that it depends on the exposure and other factors (but the challenge is keeping them clean, in a week they are already too dirty). https://www.rsi.ch/info/svizzera/I-binari-sbiancati-non-serv...

by gattilorenz

7/18/2026 at 5:30:57 PM

Sorry, but both Switserland and definitly the Netherlands are further North vs a significant percentage of the USA.

Bern, Switzerland is very close to the same latitude as Quebec City, CA or Fargo, ND, USA.

The Netherlands is even further North. Due to the lower angle of the sun hitting them they might get completely different results vs here in the South-Western USA.

Also weird in the article:

> Het aanbrengen is behoorlijk arbeidsintensief.

Really? How is driving a machine over the rail labor-intensive?

by OptionOfT

7/19/2026 at 3:59:57 AM

Because there is a lot of rail. And it requires inspection.

by moi2388

7/18/2026 at 11:07:51 AM

Hopefully they have a sandblaster mounted to the same train to clean the rails first, else they're gonna have to do this again every year...

by londons_explore

7/18/2026 at 5:44:52 PM

Or they have a heavy rust converter (phosphoric acid?) built into it. Similar to a self-etching primer.

by olyjohn

7/18/2026 at 3:13:53 AM

this isn’t the point of the story, but is that paint truck driving on the railroad tracks?

by dupontcyborg

7/18/2026 at 3:45:57 AM

Yes, they're called "high-rail" or "road-rail" vehicles. They have rail wheels that can be lowered down to drive on tracks or raised up for road use.

by LarsAlereon

7/18/2026 at 4:12:39 AM

And sometimes the axel is short (narrow), so the tires are on the rail. It's funny to see them on a standard road.

by edoceo

7/18/2026 at 11:23:06 AM

They just use custom rims.

by cucumber3732842

7/18/2026 at 1:28:06 PM

20 degree drop. That’s crazy

by Havoc

7/17/2026 at 11:38:07 PM

Practical Engineering already explained the correct solution to this problem:

https://youtu.be/zqmOSMAtadc?si=UUlmnk9sI-leq0SV

But of course, American infrastructure was built on the cheap, and is not maintained correctly. This is why we can't have nice things.

by jeffrallen

7/18/2026 at 12:04:49 AM

Why couldn't this also help with continuous-welded rail?

Your own video points out that it's still prone to trade-offs: rail breaks in the cold are better than buckling in the heat, but what if you could reduce the high point with white paint so you could expand the practical temperature range?

by anonymars

7/18/2026 at 12:21:24 PM

Or paint that turns black at low temp and white at higher temp?

by brookst

7/21/2026 at 12:58:01 AM

This is what I want on my house and my car

by HappMacDonald

7/18/2026 at 11:29:34 AM

> American [rail] was built on the cheap, and is not maintained correctly

edit: I'm not sure anymore; I know most of the network is well maintained, but there could be large sections that are not, I'm not up to date on it.

by cgyvbunji

7/18/2026 at 11:34:13 AM

It's certainly been doing better since the previous US administration put some cash in the infrastructure jar.

2025 Infrastructure Report Card | ASCE

  The 2025 grades range from a B in ports to a D in stormwater and transit. For the first time since 1998, no Report Card categories were rated D−. Among the 18 categories assessed, eight saw grade increases.
~ https://infrastructurereportcard.org/

I dare say the next report card might not be so rosy.

Rail: B-

~ https://infrastructurereportcard.org/cat-item/rail-infrastru...

by defrost

7/17/2026 at 11:59:02 PM

We have like 220,000 miles of railroad. We do have nice things: a working freight railroad system that helps reduce transit costs.

by kylehotchkiss

7/18/2026 at 12:59:19 AM

If the freight rail system were as good as it should be, long distance trucking would be a rounding error instead of the dominant freight mode.

by AlotOfReading

7/18/2026 at 1:24:56 AM

Trucks and trains serve different purposes. My understanding is the US has a higher percentage than most of freight carried by rail. Indeed at the expense of its passenger rail

by anonymars

7/18/2026 at 1:56:08 AM

Airlines killed passenger rail, not freight. Prior to it all being rolled into Amtrak virtually every railroad was losing money on passenger service.

by TylerE

7/18/2026 at 11:08:53 AM

The Post Office shifting mail transport from trains to planes is what changed the economics.

The passenger trains also carried mail, which helped make them profitable. Then the mail, and the money, moved to passenger planes.

by reaperducer

7/18/2026 at 6:07:33 PM

Canada is moving away from moving regular mail by air to cut costs.

Dunno if it will move by train or truck.

Probably too late to add much volume on the ground.

by Scoundreller

7/18/2026 at 2:51:23 PM

Italy has been doing this for decades.[citation needed]

by simon04

7/18/2026 at 3:20:40 AM

> Union Pacific Is Tackling Rail Heat to Keep America’s Freight on Track

Someone talked to an LLM which convinced them they had a brilliant idea.

Just a guess ...

by kazinator

7/17/2026 at 8:42:45 PM

Reducing derailment by decreasing track movement by painting the does of the track white, to reflect heat absorbed from the sun.

by dnemmers

7/18/2026 at 4:19:16 AM

- maybe consider electrifying the entire freight network of the USA like some of the other countries have done (mind you very large countries)

- then you might not have to worry increasing heat levels that much

by vivzkestrel

7/18/2026 at 6:35:37 AM

Why would electrification prevent track from warping due to heat from the sun?

by gblargg

7/18/2026 at 6:49:18 AM

cuts down carbon footpriunt which in the long run ll help cut down temperatures

by vivzkestrel

7/18/2026 at 8:55:21 AM

There's a lot more low hanging fruit with higher payoff than optimizing all rail in the USA.

Also, a guess, but I think you might benefit from checking out the actual size of countries vs the Mercator projection size of countries.

by Paradigm2020

7/18/2026 at 10:46:03 AM

If we are in the long run stabilising that would be already a win. Until the temperatures go down it will be a long, long, long time if ever. So temperatures will go up and we have to adjust. The scale of required adjustments is not understood yet and the increasing number of surprising needs to adjust is scary.

by heisenbit

7/18/2026 at 11:14:22 AM

If we get to a point where direct sunshine all afternoon isn't hot, we're going to be in a big block of ice.

by gblargg

7/18/2026 at 4:37:23 PM

there’s a genius here, the crème de la crème of today’s thinkers

by throw1234567891

7/18/2026 at 2:26:21 AM

Paint everything white! Why stop at rails?

Mostly because it doesn't stay white and looks bad. But it doesn't stop people from painting their siding white, for example.

Why paint the sides of the rails? Well you can paint the tops, but it tends to gum up the wheels and get worn off.

You want a paint with high reflectivity and high emissivity. Just be sure you aren't using infrared light temp measurement as to measure and make claims about differences in temperature, emissivity is something to watch out for when measuring temperature in that way.

20 degrees is surprising, I sure wish my car was white in the summer.

I wonder if you have okay effects with white rails in the winter?

by acyou

7/18/2026 at 3:23:08 AM

The top of the rail is already white!!!

It's just polished, so that it is reflective.

If you sanded it with your 180 grit paper, you would get the scattering which appears white.

by kazinator

7/18/2026 at 3:20:44 AM

> Why paint the sides of the rails? Well you can paint the tops, but it tends to gum up the wheels and get worn off.

Tops of rails are already pretty shiny for any mainline track seeing a couple dozen trains a day. I'd bet they are more reflective than white paint could be. And the paint would be gone after the first train passes through anyways.

They rust pretty quick, but with regular use it doesn't build up much since it's constantly being worn off from the wheel friction.

by phil21

7/18/2026 at 3:59:55 AM

Thank you, I was wondering why the need for paint rather than side polishing and the added knowledge that this blend of Steel rusts would ruin that for the non-contact surfaces.

Painting it cheeper than polishing. But I wanted to know the reason they needed to / that made it so.

by mjevans

7/18/2026 at 8:44:18 PM

I recall a test initiative was done some time ago for painting (or mixing in, I forget) roads teal. It improved the heat island where it was placed, and wasn't too bright for motorists. I wonder why that never went anywhere...

by MrDrMcCoy

7/18/2026 at 3:23:45 AM

You can literally buy derailers[1]. People will find away around this, making white paint useless. Engineers need to engineer.

1. https://www.aldonco.com/product-category/derails/

by kelseyfrog

7/18/2026 at 5:21:54 AM

this is tackling regular natural derailment incidents not terrorism

by hhh

7/18/2026 at 5:29:28 AM

Derailers are common and are placed where people are working on tracks so a runaway car will go off the tracks instead of hitting the workers.

by trollbridge

7/18/2026 at 3:31:03 AM

OK, but a heatwave isn't going to buy a derailer

by advisedwang

7/18/2026 at 4:10:12 AM 

   Do NOT use where speeds exceed 5 m.p.h.
Not sure what you're thinking of, but these widgets you linked won't solve the problem of long rail sections heating up in the sun, buckling, and derailing freight trains travelling at normal speeds.

by defrost

7/18/2026 at 2:19:29 PM

Why worry about memory safety? Users can literally "kill -9" anyway.

by StilesCrisis