How Do Potholes Work? 

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So, funny story about that whole having paved roads thing... here in Illinois, we have a saying: "In England, we drive on the left. In Illinois, we drive on what's left."

In my country, the government has managed to significantly reduce the costs of road maintenance by simply not doing it. edit: from Hungary, stop asking

how potholes work: truck drivers wait till they're full of water, then hit em with every wheel they can.

Grady, you're an example of what's right with the engineering, education, RU-vid, and the world in general. Thanks for your example and efforts in this video and others!

4:18 In Canada we have four seasons: Almost winter, winter, still winter, and road construction.

"How do portholes work?" It works when the government doesn't.

“The only thing that gets bigger the more you take away” - reminded me of Brok’s riddle all over again in GOW

"Driving is a little dull." Miata Drivers: "I'm gonna pretend I didn't hear that."

Therefore, in Russia there is an expression “spring has come and the asphalt has melted along with the snow”.

Your channel inspired me to study civil engineering, now on 3rd semester.

This sheds some light on a recent mystery for me on my residential street actually. We had this one spot that kept developing pothole - but what I mean here is not "once a year," instead the asphalt was disintegrating after every single heavy rain! And living in the southeast USA, heavy rains are REAL common. Eventually the city came in and did a bunch of digging, a trench across the width of the street - that poor crew had to spend almost 14 hours digging up something and then putting it all back. Later on I found out from the neighbor, there was a city water pipe that had some kind of leak or crack...and I'd wondered what on earth that had to do with the road. No one had needed to boil their water or anything like that, so I thought "how bad of a crack could it have been?" But learning this - I understand much better now - it wouldn't need to be a big crack at ALL to make the dirt beneath the road way erode. And when the city tried just patching the potholes - the water pipe was still the problem. So naturally the rains just took away the patch and widened the hole even more!

This video is a really great understanding of the industry and the logistics and bureaucracy involved. I run a road work crew and I work flat out trying to repair potholes but as much as I can fix them, I have one crew with a city of 45 suburbs and thousands of kilometres of roads. My brief is to rapidly make them safe until a patching crew can repair them permanently. Unfortunately I have to return to some sites multiple times because there are not enough resources to go around to fix every little pothole permanently, hence the constant bandaids. Besides, it’s not cost effective to send an entire patching crew to repair a tiny road section. It’s a trade off between permanent repair and coverage of an area. I work a dangerous job where I’m constantly on the road and as I’m visible to the community cop the understandable ire of them, but I’m working hard to make the roads safe and I also live in the city and actually care so a little understanding from the community and education would go a long way. The irony is people get annoyed that you’re impeding traffic briefly but also want the problems fixed.

This guy matches almost perfectly my stereotypical image of an engineer... And he's good at what he does. Accurate explanation, easy to understand. Thumbs up

"something we've all experienced once or twice" Yeah, once or twice a day

I definitely would not consider myself an engineer, I cook for a living and am terrible at math. But you have made learning more about engineering so fun!!!! Thank you Grady!!!

I am a trucker and just discovered your channel. I am the guy who likes driving and do 600 plus miles per day its really cool learning how the stuff is built i use everyday. Keep up the good work 😁

"Something we've all experienced once or twice"- Once or twice every minute here in South Africa.

"Potholes are worse in freezing conditions-" They're even worse in a corrupted system.

I was an engineer at the site of a new road, when we were done I took a crew with what remained of the asphalt around town and hot-patched as many potholes as I could find.

Pot hole stories: When I was nine in jamaica my uncle put me on duty to watch out for pot holes (it was at night) I was pretty good at finding them During my last trip to jamaica my uncles van was losing so much gasoline, when we where leaving we found out the problem , a pothole caused the gas tank to leak, That’s my pothole stories.

The biggest reason most potholes come back is they don't address the underlying issue. The subsoil is not stable. In my area(the Texas gulf coast) we have a high clay content soil we call gumbo. It has very high amounts of hydraulic movement. To prevent this, the subsoil is now stabilized by mixing in cement for 10-14 inches, before the base goes down. That prevents most potholes before they start. To repair a pothole, they dig up enough asphalt and bas to get a tiller down to the subsoil and do the same thing. Then they put it back together in 1-2 inch lifts.

"Colder countries have more potholes." Indian politicians: we'll prove you soooo wrong.

This is why it is so important to not drive into flooded road. You have no idea how much has actually eroded under that water and in major storms it can be a shockingly large amount of missing road and subgrade.

I wake up excited to drive. Driving is a highlight of my day. I drive further on purpose. I bought a manual on purpose. I absolutely love to drive!

A perfect pothole postulation at this early hour.

"Politicians, government officials... drive on the same road as everyone else" Hahahaha that was a good one, I'm crying

"How do potholes work" are you telling me they deliberately made potholes to work on destroying my car? damned conspiracy! i knew it!

I suppose it depends on the environment, but I thought there was a lot of evidence showing roads with a concrete base cost significantly less long term because of the reduced maintenance cost. As well, when they do need resurfaced, it is pretty simple as the foundation will most likely still be fine. Here in the UK, we tend to use very cheap, simple road designs, and it definitely shows. We also route all utilities under roads by default, which means that, even when you do get a nice new road surface, within a year a utility company will have been granted a licence to dig a massive trench through it and leave it with a big patch that will inevitably cause a pothole pretty soon. Madness. The fact that we route utilities under the roads actually incentivises us to use bad road designs as the utility companies don't want to have to dig through concrete every time they have to service the infrastructure.

Biggest thing that helped in my city is that they were no longer immune from liability due to damage to cars caused by potholes. That fixed things pretty quick when the insurance company started going after them.

My country has marvelled this technology..we have cutting edge potholes BTW I am from India.

Long ago, when most roads were dirt, each village would have an assortment of craftsmen. Blacksmiths, carpenters, bakers, potters etc. Sometimes, when asked to make a pot, the potter would look for the most finely pulverized clay around and often find it in the wagon ruts of a nearby road. When he dug up the clay for his pot the hole he left was called a POTHOLE. I really enjoy your content Grady.

I think especially since working from home this last year and a half, driving has become a pleasure for me. Driving represents freedom and opportunity to me. I can go from place to place. I can go see my family. I am grateful to be able to drive. I used to commute an hour and a half each day for work before I relocated. Now I have a short commute. I don't ever want to take driving for granted again.

"There are lots of ways to build roads - from yellow bricks to rainbows" Yes, sir. I am looking forward to the new Rainbow Road episode.

Grady: How do potholes work? Well I never knew they were a feature.

“Something everyone has experienced once or twice, let’s talk about potholes.” *Laughs in Michigan*

Have never really come across potholes in my country! The Netherlands really does make some great roads and other engineering marvels.

"So, roadway owners spend a lot of time and money fixing them" *ha-ha*

I sure wish I could force my taxes to be spent on roads and infrastructure.

This is one of the channels where you can like every video before even seeing it. I love the explanations with the small flow models and so on, it’s just great!

I will say, having paved roadways everywhere is certainly something taken for granted. It truly is a monumental task. I will add that the first time I bought a sports car, I did look forward to driving everyday. You don't even have to speed. Everything in the experience is enhanced.

"Roadway owners spend a lot of time and money fixing them (potholes)." Press X to doubt.

"Something we've all experienced once or twice" Idk. In Chicago you'll experience it once or twice per block.

Thank you for appreciating highways and understanding their massive importance and the huge challenges faced maintaining them for everyone.

this is why i love these videos.. i started off thinking, i know how potholes form, why do we need a video on it? and halfway thru i was learning so many new things and it's logical and lovely 😌

Title: "How do potholes work"? Answer: They don't work

"You've all experienced potholes at least once or twice" *laughs in Michigan*

I've been thinking about this for decades. I'm usually pretty good a figuring out cause/effect just by thinking about it long enough. Potholes had me stumped. You have just freed up so much background brainpower, you have no idea. Thank you!

That’s crazy because ALL I look forward to in the morning, at work, or even out wit friends, is the moment I get to get behind the wheel. My favorite part of any day. Driving provides me with clarity and focus like nothing else does

Practical Engineering: How do potholes work? Literally everyone: They don't.

For all the German viewers out there: Yes this is real, it's not a prank video, or an April Fools'. We actually have lots and lots of potholes where I live.

Thank you Grady for opening my eyes! you make me appreciate things that never even crossed my mind before. JOINED!

Imagine how good the roads would be if the government was required to pay for any vehicle damage caused by potholes and other road defects

In Japan : "Wow, that's a potholes !" 3 days later, no potholes In Indonesia : "Wow, that's a potholes !", a year later, the same potholes still exist (even bigger than before)

6:40 I love your explanation of how we "choose" potholes. Please run for public office.

I hope this video remains publically available and doesn't get hidden or deleted. I find this kind of content absolutely fascinating.

When watching channels like this, I keep asking myself... Why wasn't the high school or the university so interesting and fun in their presentations?

One of the benefits of being interested in cars, driving is almost never boring. I'll drive for hours on end and love it.

I can explain exactly how potholes work in Illinois. Step 1 - Build the cheapest road possible. Step 2 - Wait for potholes to develop. Step 3 - Campaign for re-election on fixing the potholes. Step 4 - Get re-elected. Step 5 - Repair the potholes in the cheapest possible way (using one of your favorite campaign contributors). Step 6 - Wait for potholes to reappear. Step 6 - Repeat for your entire political career.

Great video The physical demonstration done in the glass tank was genius

This has become my new fav channel to binge. Thank you!

1:45 Yellow brick road: Wizard of Oz Rainbow road: Mario Kart

Over here on clay soil, I see that 30cm of gravel and 15cm of iron-smelter residue is used to drain water to the ditches. The smelter rocks are not as easy to wash away.

I love all the slow-mo shots of cars hitting potholes. It's funny, but also oddly satisfying.

I love the title. "How do potholes work?" Based on our county I believe they probably have a "pot hole machine" that makes pot holes since we are in a dry climate and we have more pot holes per mile of road than any other county around us. Been looking on the heavy equipment sites for a "pot hole maker" such as Cat, John Deere, Komatsu, etc. and did not see one listed. They must have had it custom made.

Title: How potholes work me : What a boring topic Channel: Practical Engineering me: Click! At this point I am myself surprised at how interesting you can make the most mundane of things. I cant have enough.

Driving isn't a dull experience imho.... especially when it's a manual. As a paper pusher, my most fulfiling moment of the day is probably my commute.

how appropriate that this showed up in my feed today. It's spring, and there are a lot of potholes gradually being uncovered as the snow melts. Now we've had another snowstorm and temperatures dropped below freezing again, so a lot of water probably froze underneath the tarmac, giving us even more potholes when it warms back up.

Potholes in western PA were a constant problem in the heavy industry traffic and servere winter days from decades past. Most of the road weren't treated with tar for some reason but the few that were treated with tar held up very well. Some were tarred and sprinkled with rocks. They never got potholes.Nice explanation of the pothole process.

"You've all experienced potholes one or twice" man here in Balkan countries there is no street without potholes. Except in highways but in Croatia the highways do have potholes

You can't put googly eyes on a pothole. They're soulless.

Always love your videos! Thanks for the great explanations.

Think of them as miniature sink holes and you’ve pretty much nailed it;)

“Poor condition” is just normal where I live. It is so nice when I find an area that was just paved and it suddenly feels like my teeth aren’t being shaken out of my head. Even then, it’s not always great. My local grocery store’s parking lot was getting a lot of pot holes so they repaved it. I’m pretty sure that they just put down a new layer of asphalt on top of the existing layer instead of properly tearing it up and flattening the ground. I realize parking lots are extremely busy areas and need to be constantly available, but half-assing a job is almost worse than not doing it at all. Louisiana does not know how to make roads. Even our highways aren’t made properly. One exit on I-10 has a huge bump in it. Granted it’s not that big but going over it at 45 mph is more than a little jarring. It’s not surprising that so many people here have crossovers or trucks with tires with high sidewalls. My wheels probably would have been destroyed by now if I didn’t have really tall tires

In humid tropical regions, potholes also form at a very high rate. There's no freeze-thaw action, but there is a seasonality in the subgrade's performance, depending on the alternation between wet and dry seasons. During the dry season, clay soils are hard and sturdy, and thus provide excellent support for the weight of vehicles. When the wet season comes in, water infiltrates and induces things like plasticity (clays absorb water and become soft and pliable), expansion (some clays absorb water into their molecular structure and increase in volume, much like the ice lenses in freezing conditions) and drainage problems (clays are less pervious than sands, gravels and loams), so the water often is limited to escaping under pressure through cracks and weak seams.

I’ve only been driving for a decade, but I’ve loved every minute of it. Just have to be into cars, and have a fun car to scoot around in. The highlight of my daily grind is the half mile long empty road on my commute.

As someone who rides a motorcycle a lot, pot holes are my number 2 fear. A middle aged Karen on her mobile while driving a minivan full of screaming kids is my number 1 fear. Oh and all while she is smoking a cigarette

This guys sounds like he has a phd in talking

"I dont wake up in the morning excited to jump in the car for my morning commute" Sounds like you need a more fun car, man.

Hi Grady. I enjoy your content. Here's something you might enjoy. Pot holes get their name in an interesting way. As you point out, roads have been around a long time. In the earliest days each community or village would have a compliment of the necessary craftsmen to fill the needs of the local population. Among these, of course, were potters. Potters knew the best soil for throwing pots was that which had been pounded until there were no clumps or stones in it. So they would dig holes in the ruts created by cart wheels as it had been naturally pounded to fine clay. The hole they dug out for pots we call pot holes. Ask me where we get the word " threshold ".

"So, roadway owners spend a lot of time and money fixing them" America: What is this fixing you speak of?

1:46 Grady I don't know how many rainbow roads you've driven on but I wouldn't exactly call them the pinnacles of contemporary engineering and safety. 30+ years yet they keep installing those blue shells

"So roadway owners spend a lot of money to fix them" _Looks at the pothole that has been in the parking lot of our local supermarket for over a year_

The great thing about dirt roads is that they don't need to be maintained and the only thing you need to worry about is downed trees/foliage. If there's a pothole, just fill it with dirt from the roadside! You can also get a nice mud bog paint job after it rains. Yee yee! 🤘🤠

They work by allowing the director to conveniently skip over a device that creates questions by the audience that are ignored. Hope this helps! Edit: oh not plotholes

"So, roadway owners spend a lot of time and money fixing them" haha, yeah. It's a shame I live in a small city so they can't afford to fix the half-dozen potholes I have to swerve to avoid every night I'm driving home from work. Oh, but those new rustic streetlamps they put in and the crosswalk signals that nobody uses because there's like maybe three pedestrians a day sure do look really good!

As a professional driver, potholes are my arch nemesis, they must all be destroyed.

When I attended the USAF NCO Academy the best speech was by a Civil Engineering troop explaining how to correctly fix potholes vs. the cheap "throw and go" (he said that was the industry term) method of filling with asphalt. Interesting stuff insightful to best practices.

I love driving! I love being able to travel hundreds or thousands of miles on a whim realizing that level of personal freedom never existed before. I am on a road trip vacation as I type This. In the last 7 days I’ve driven 2300 miles and seen swamps, deserts, mountains, other countries! What is not to love?

@Practical Engineering - could you cover this topic more with explaining hydrostatic shocks? As I've understood it, upon hitting the water in a pothole, the resulting shock causes the water to be forced in to the road sublayers in macro- and microscopic fissures - and pumps out material as the water is squeezed (almost instantly) back out by the re-compacting ground as the fissures collapse. Like lightly stomping on a puddle on grass repeadetly causes the water to muddy up as fine particles are brought to the surface. If you continue and increase the force, material begins to be removed from the effected area by being ejected outwards. Now do this with traffic and you are literally pumping material out of the ground. The fissures ever deepen as the lessening of fine particles allows for water to be forced farther and farther, as there is nothing to dampen it's flow among larger paeticles. So you'll end up in a volume of material beneath the hole that's been rinsed with pressured water maybe thousands of times, fracked, decompressed, compressed. Rinse, repeat. I don't understand how fixing the situation could only include resurfacing, as now you're resurfacing a structure that's not the same as what surrounds it - the near-0-sized particles are missing and stable compaction cannot be achieved without those. So, what you're resurfacing is a moving, shaking, altering structure. This is a huge issue here in Finland.

1:47 Rainbows?! Someone's been playing a lot of Mario Kart lately

I thought you were going to say "driving on bad roads has become a form of entertainment."

I’m originally from Montreal, where roads and other infrastructure take a lot of maintenance to to seasonal large temperature fluctuations (+/- 40 deg). They’ve built a few highways using a concrete with polymers, no asphalt top layer. They’re as good now as when they were installed over two decades ago.

Potholes : *exist* Drivers ; "what a bummer" Cysclists: *exist* Potholes : "I"m about to end this man's whole career"

Best part of the day, the morning commute. Quiet, just me and the car, the engine, in harmony going down the road...

my morning and after work commutes are some of the best times of my days!

How to fill a pothole 🇮🇳: Let the monsoon rain do it.

7:40 I don't know how it is in the US but in Australia it's a major part of our engineering education.

He reminds me of the nerdy teacher I wish I had. I love your videos I learn so much and you teach it in such a simple way

I wake up just to go for a drive sometimes! Between just loving to drive, and having a good audio system, I like commutes.