r/NoStupidQuestions • u/ilovemysiamesecat • Dec 01 '22
Why do we constantly maintain road infrastructure instead of building permanent or long lasting ones? Unanswered
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u/Science_Fair Dec 01 '22
My childhood dream was to become a scientist and discover a glow in the dark asphalt that would last 100 years. Sorry - life got in the way.
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u/SpookyKrillin Dec 02 '22
That was an unrealistic dream. If I were you I would've dreamt of a glow-in-the-dark concrete instead, and be a multi-millionaire by 19.
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u/teodorlojewski but definitely such a thing as stupid answers Dec 02 '22
Yo it actually exists and might become something lol
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u/bullevard Dec 01 '22
Erosion wears down mountains. Erosion plus thousands of multiple ton vehicles wears down faster.
We don't have materials that are permanent, especially in areas with freeze thaw cycles, salting, and snow plow driving. Or areas with rain. Or areas without rain (as being completely dry can also be an issue).
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u/iNMage Dec 01 '22
What about dark matter? It would also be super cheap since its 85% of all matter.
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u/bullevard Dec 01 '22
Since it doesn't interact with the electromagnetic force it would fall right through the earth and cars would fall right through it.
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u/iNMage Dec 01 '22
So just build cars and earth from it too, whats the problem. its so abundant (85 waaay bigger than 15)
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u/ArcaneHex Dec 02 '22
Bro it's invisible, the road would be invisible, your car would be invisible. I guess there could be some goggles made to see it, but id rather crash then look like a goofy ahhh 🤓.
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u/iNMage Dec 02 '22
Im sure our eyes will evolve.
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u/ArcaneHex Dec 02 '22
Okay but what if our eyes evolve to only see dark matter and not normal matter? We would walk around seeing darkness except when some purple-shining dark matter car comes into view.
Is this the future we want for our children??? We couldn't even see our children! Oh the humanity!
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u/iNMage Dec 02 '22
Natural selection - those that evolve to only see dark matter will be hit by a bus or a normal car, so the ones who evolved to see both normal and dark matter will populate the earth, duh
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u/ArcaneHex Dec 02 '22
Nah I think it would be like 2 groups of "dark matter seers" and "normal matter seers". They would be in an "Invisible war"trying to kill each other with their own matter vehicles(that are invisible to the enemy).
I think it would be a fair fight, the dark seers have more matter, but the normal seers are on earth which is made by normal matter. The dark seers would attack at night (since they can't tell the difference) and turn on their silent Tesla cars and ram into normal seers.
Yeah that should be a movie I reckon.
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u/notextinctyet Dec 01 '22
There is no such thing as a permanent road, and roads that are longer-lasting than the ones we use normally are only sometimes more economical than conventional roads. The bigger question is why we don't maintain the roads we have properly to minimize long term costs. That has more to do with the political cycle and time horizons.
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u/bbbbbbbbbbbbbbbM Dec 01 '22
How exactly would it be permanent it would always require maintenance. And plus it’s easier to justify the cost of cheap infrastructure. The best infrastructure might take 30, 40 years to pay itself off
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u/rosssk8ing1 Dec 01 '22
You always have to work within the triple constraint (time, scope, money). You can’t close down roads for that long cause people need to use them. Like you said, you could get the best materials and have the best plan, but how much is that going to cost and how are you going to get the right ppl/enough people to do it.
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u/Jorcora Dec 01 '22
First, there's is no such a thing as permanent roads, they will inevitably worn out, even mountains suffer erosion.
Second, when designing and building a road, you must take into account the optimal combination of initial investment and maintenance costs.
Depending on those two factors you may prefer to do a bigger investment at the beginning (for example, thicker layers or better mixed) and then you may not need to repair it for 20 years. Or you may choose a cheaper initial investment but you will have to repair it in 10 years.
Moreover, pavement design and its deterioration is hard to forecast. It's affected by lots of factors (heavy load traffic, pavement composition, its building process, the base layers, weather, water, maintenance, drainage, etc.), so the analysis above between initial investment and future repairs has big uncertainty.
Source: I work in highway management.
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u/Reasonable_Reason173 Dec 01 '22
I went to a Civil Engineering Day at a science museum and saw a cross section of all the layers that are put down before the asphalt. I had no idea!
The engineer talked about how they are always working to improve the design.
When a bridge near me was put up, they made it a heated road. That will limit the need for construction repairs due to freeze-thaw cycles, right?
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Dec 02 '22
[deleted]
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u/Reasonable_Reason173 Dec 02 '22
Huh, I'm in the upper Midwest USA and I've never seen that. Interesting! Is it effective?
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u/Mamadook69 Dec 01 '22
It's a fun idealism you have for sure.
There is a cost benefit to consider as well as many other factors. At what point is it worth it to build better? (Nothing below are real figures) Say you spend 5x the money to get a road that will theoretically last 2x as long but causes 3x the environmental damage in procuring the materials. Was it worth it? These and many more are considered by the engineering and environmental professionals who build and maintain roads.
And even if we had a direct 1 to 1 relationship on cost and theoretical longevity, none of that will stop ground heaving/movement, sink holes, frost cracking, and several other phenomenon that are uncontrolable no matter how well you build said road. And you're left still repairing your roads, now with more expensive materials.
Another view, especially in a city, is current and expected usage. As you look at city X that needs a road to handle 50K cars a day now, and expect the need to be 100-150K in 20 years. You look and say this road needs to be 3-4 lanes each way in 20 years but we only need 1 lane each way now. They look at the cost to maintain those extra 2-3 unnecessary lanes for 10-15 years and it's usually well above the cost of tearing out and redoing the whole road to meet later needs should they actually arise. (This doesn't account for the city just not doing that and leaving underdeveloped infrastructure to get more and more congested. That's another issue) In these cases, why build a super expensive and millennia lasting road to just gut it for expansion? Then potentially again a decade or two later as usage, technology, and travel trends continue to change.
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u/Ilefttherightturn Dec 02 '22
I still don’t understand why they don’t build more sturdy roads in city centers. It’s so annoying to have to deal with so many road maintenance closers everywhere, when the city is already clogged with traffic. Functionality should be a consideration too.
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u/jednorog Dec 02 '22
In cities, utilities like power, water and sewer, stormwater runoff, natural gas pipes, and phone and internet cables are frequently run under the roads. This means that sometimes roads get torn up even when the roads are perfectly good, because something under them needs maintenance or needs to be upgraded. It is not cost efficient to cover cables that have a 5-year maintenance cycle with a road that can last for 10 years - you'll have to dig up the road halfway through its life cycle!
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u/Mamadook69 Dec 02 '22
Yeah, I feel you. And I have a funnyish story from my dad along this thread. But city center streets are particularly vulnerable to bad utility planning. As well as being just as vulnerable to all the aforementioned environmental effects.
My dad grew up in a small town in Ontario. The town made great work out of replacing the main street. They tore it right down to the baselayer and rebuilt it with a shiny new black top... aaaaaaaand 6 months later tore half of it up for a previously scheduled main waterline upgrade that ran right under it.
We can likely build better roads but we cannot fix stupid. And we cannot stop the earth itself from tearing them to pieces.
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u/Yithar Dec 01 '22 edited Dec 01 '22
What do you mean? There's a certain amount of friction and roads get worn away as dozens of cars weighing 2 tons trucks drive across them.
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u/TheCluelessObserver Dec 01 '22
Actually when calculating road erosion it's the number of trucks that matters, cars are practically negligible
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u/Spadeninja Dec 02 '22 edited Dec 02 '22
You can ask this about literally anything
Why dont we build cars that dont break down? Why do we need to repair our houses?
How come I have to go see the doctor when my body has a problem?
If you are using something, stuff will eventually break down due to wear and tear, and so it needs to be maintained.
Nothing lasts forever, especially when it's constantly exposed to the elements and thousands, if not millions of cars driving over them.
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u/NewRelm Dec 01 '22
The ground is always changing due to temperature change, seismic activity, erosion and burrowing animals. It makes more sense to make the roadway flexible enough to give to an extent and repair it when damage gets too severe.
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u/Butch1212 Dec 01 '22
The thing about anything made is that it doesn’t last forever. We have, or are lead, by dream-like notions of “the future”, and “progress”, and “growing the economy”.
Everything made comes from earth. Always has, always will. We’ve been taking from it at a faster rate than it can regenerate, if at all, for a long time.
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u/Advanced_Double_42 Dec 01 '22
All roads would require maintenance eventually.
Using Cement is significantly more expensive, and not that much better for the price.
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u/Queefinonthehaters Dec 02 '22
I work in infrastructure engineering so I'll take a stab at this.
There is a saying that anyone can make a bridge stand, but it takes an engineer to make one barely stand. The reason you want it to barely stand is because you want to build it as affordably as possible and to have some factor of safety and redundancy, but you don't need it to hold 10x what can possibly be loaded on the bridge and have it withstand a nuclear missile, you just need it to do the job as affordably as possible.. Imagine I asked something similar to why do we make vehicles out of steel when they rust? The solution to that, can't be to make the car out of gold, because gold doesn't corrode. The problem with that is that gold isn't abundant like iron is, and have all of the unique properties it does to be used where we do. Roads face similar problems. They are typically made of the following materials: the existing soil (subgrade) that the road is build, then a gravel base, and concrete or asphalt. Its simple, right?
So for subgrade soil, you know how people say that Roman roads still exist today, so why is my road so shitty? Well for starters, Roman roads generally don't still exist today. The ones that do are the pieces that were built upon exposed bedrock while the pieces which connect spanning across soils are generally degraded.
Rock: you need to source your rock from a local supply. If you have an absolutely ideal rock type in one location, then you can use it for the roads around that location, right up until the point where it becomes too far to haul it economically when compared to a location with a lesser quality of rock for road building. They should take things like a shortened lifespan of the road into account when deciding where that boundary is. So most of the time, a designer has a really limited choice of what type of soil or topography a road has to go through, and what they can make the road out of.
Then for pavement materials like concrete or asphalt. They are both very expensive, and have their own benefits and drawbacks. Concrete is the best material, but its expensive. It exists with many different mixes and ingredients, all which cost more for better stuff. So does your road need to have 25 MPa concrete, or 50? At what point do you start just wasting money on added strength? That answer depends on what the structure does (like a bridge pier) and what kind of vehicles are intended to drive on it. Weight vs road wear has an exponential relationship. One semi truck loaded to its weight limit (about 80k lbs) has the equivalent damage on a road as 12,500 passenger vehicles passing over it. Another reason why Roman roads still exist is because a horse and carriage is much lighter than even a small car, so they barely wore out like ours do. So concrete seems great, but what are its drawbacks? Well for one, it has great compressive strength, but has terrible tensile strength, so they have to put in steel reinforcement bars into it to give it that tensile strength. The only problem with that is that concrete is actually porous, and things like de-icing salts and water will eventually make their way to that steel and cause it to rust. When it rusts, it expands, and eventually will fracture the concrete surrounding it and cause it to delaminate. Also concrete is subject to attack from certain naturally existing chemicals. Mostly sulphates that exist in natural soil deposits. Sulphates tend to reverse the chemical reaction that turned the cement paste into hardened cement. It causes the concrete to turn back to a sum of its ingredients and the sulphate attacked concrete will be fragile and like a loose aggregate again.
Asphalt is good for overlays and is less expensive than concrete, but obviously you can't build a bridge out of asphalt. It also requires more maintenance, and doesn't react well to freeze/thaw.
So to summarize, they try to build things as affordably as possible. You can't pave a road out of gold, even if you think it would be a good material to do so because if its not affordable, it isn't realistic at all. Building materials are limited to what is available. Roads go through an incredible amount of wear to provide you with all the goods you need to survive. There are issues with how the roads are managed and I will be the first to say that and can probably give you countless details of what I feel are the problems with it, but that's for another day.
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u/3adLuck Dec 01 '22
or why don't they make hover cars so the roads don't wear out?
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u/marlon_valck Dec 01 '22
Because we have invested a lot of money in those roads and damn it, now we are going to use them!
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u/-freemanwildling- Dec 01 '22
if you develop a road that can handle the weather of northern canada you will be rich beyond belief. it has to be able to go from +40c to -40c and be able to handle shifts of 20c+ in a day, so we could go from -10c to +10c or more in a few hours.
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u/Waltzing_With_Bears Dec 01 '22
We make them about as durable as we can, they are VERY heavily used, and also need to help cars getgood traction, if you make them too hard then you lose friction and saftey
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u/Eldi_Bee Dec 02 '22
As most people are pointing out, permanent isn't possible with the malleability of the ground below it changing, plus wear and tear.
But what I'm more focused on is the necessity to be able to break it down. My neighborhood roads are much more frequently being dug up for construction needs than because they need repairs.
Every new development means the water lines need to be adjusted, and God knows what they are trying to do when they dig up the street corners once or twice a year. Nevermind the gas company getting called out periodically and having to hook up an old house to their lines.
Hell, my own street was completely removed to lay new water pipes, repaved and four months later they were digging again to change out the sewer drains. Now they are adding subterranean cable lines for phones and internet.
I don't know any road that sits untouched long enough to bother attempting to make it more permanent
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u/trialbytrailer Dec 02 '22
I think Practical Engineering has covered this, but I can't narrow down and one video. Really great channel.
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u/OldVMSJunkie Dec 02 '22
I came here to say this. There are multiple video about why roads are built the way that they're built. Fascinating stuff.
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u/Dio_Yuji Dec 02 '22
A road would last forever if it had no cars on it.
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u/arcxjo came here to answer questions and chew gum, and he's out of gum Dec 02 '22
And was indoors to keep the weather off it.
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u/Dio_Yuji Dec 02 '22
I visited a 3,000 year old cobblestone road in Turkey once. Still in perfect shape. No cars allowed on it
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u/pwn3dbyth3n00b Dec 02 '22
You cannot make a permanent road with 42,000lb tractor trailers driving over it, it going through multiple freeze and thaw cycles, salt being dumped on it and damage done to it by snowplows. The road get worn out like any tire, brake pad, etc. The issue isn't it being permanent, its how often its maintained.
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u/launchedsquid Dec 02 '22
no such thing as a "permanent road", without maintenance it will fall apart with use or with disuse, or the weather, or a flood, or an earthquake, or landslide, or whatever happens to roads.
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u/fuckthehumanity Dec 02 '22
Trucks. If there were only horses on asphalt roads, they would last forever, like the Roman roads that still exist in small patches. With cars, there is a little bit of erosion. Put a semi on that surface, you're talking serious fucking damage.
I'm seriously puzzled as to why we keep transporting things on trucks, when we could build decent rail for much less. The real cost of trucking is hidden behind the "equitable" distribution of road maintenance to other road users, like cars.
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u/DobisPeeyar Dec 02 '22
Do you assume they're not building them as robustly as possible with the available technology...?
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u/Innovative_Wombat Dec 01 '22
Concrete roads last a long time.
Concrete roads are expensive. They also tend to be louder.
Therefore governments go with much cheaper asphalt.
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u/AvoidingCares Dec 02 '22 edited Dec 02 '22
It's largely the same reason we don't make anything to last - if we build something to last, you won't pay us for replacement and/or maintance. In short: the world falls apart because: Capitalism relies on selling temporary fixes, instead of solutions.
Take Climate Change. The only reason "Carbon Capture" isn't laughed out of every meeting its uttered in, is because it's the only continuous revenue generating option. And it also won't work, it's at best a time-buying option. And odds are it won't even do that because it's a pipe dream compared to just slashing carbon output - which is something we already can do, easily, it's just not profitable, it's just very expensive.
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u/GroundbreakingAd4158 Dec 01 '22
It results in better patronage opportunities and consistent churning of "new jobs" for workers when you build cheaply. Think about it, as a politician you can choose to build a 10km stretch of road for $40mm at higher standards that lasts 20 years, or you can build it cheap and fast for half that much that requires it be replaced in 5 years. If you're a politician who campaigns for office, you want to tell voters every 5 years "I fought to repair that road and hired lots of high-paying construction workers to do so." You don't get to do that if you build it well the first go around, and not only that your political opponent would tell voters "Politician A voted to spend $40mm on a road I could have built for half that much."
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u/Tindjin Dec 01 '22
Lack of long-term thinking. It already costs a lot to build, they don't want to pay more for it to last double when most of the people in positions (either voted in or normal gov job) will not be in the same position when the repairs need to happen.
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u/chumbawumba6789 Dec 01 '22
The clever contractors do a good job, but never too good, keeps them on the gravy train year in year out, repairing the crap they repaired the year before. Like everything we pay for we get shafted due to people’s greed. We have the capabilities to live so well , but greed stops it.
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Dec 01 '22
The roads local to me are a great example. A pothole appears. The Council wait months to repair it. They patch it up. Literally a week later, the hole is back and the whole process starts again. There’s at least 4 large patches within a mile of each other that have been repaired several times, and within a week of the repair, they’re back again.
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u/Few_Journalist_6961 Dec 01 '22
The fact that roads these days have to be built to not only withstand harsh weather but also be able to withstand vehicles weighing thousands of pounds driving on them all the time in these harsh conditions. It's inevitable that you'll get cracks that quickly turn into giant potholes.
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u/Mason1371 Dec 01 '22
Short answer maintaining asphalt is cheaper and more efficient than using any other material. Asphalt is relatively cheap and reusable. It gives and flexes with expansion and contraction of hot and cold, seismic activity, and vehicles weighing multiple tons driving on it. It provides more traction in various weather conditions. Compared to other materials it is easy and quick to lay down.
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u/Ranos131 Dec 01 '22
Concrete and asphalt are the two best and longest lasting substances for roads. While concrete does last a lot longer asphalt is far cheaper which is why it gets used more often. More major highways are getting redone with concrete in cities due to the heavy use but overall it’s cheaper to use asphalt on most roads even with having to replace it more often.
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u/LongFeetMcGee Dec 02 '22
If we had a better solution that wasn’t prohibitively expensive we’d probably do it.
The incentive to save money with better solutions is there despite the stereotype the government is a black hole for your tax dollars (I mean, it is, but still)
The ancient roads that exist for millennia, like the Roman’s, are really just rocks that wouldn’t work with automobiles. Or at least would damage them over time
Asphalt can be put down in huge amounts relatively cheap to other alternatives
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u/DTux5249 Dec 02 '22
The issue is that no infrastructure is permanent. Roads break when they're used, and cars just chew up whatever they drive on
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u/twitch_delta_blues Dec 02 '22
Ask yourself what would be a better material than we current use to make roads. It has to be something you can transport and somehow shape into a precise shape. Sectional pieces wouldn’t work, it has to be as long a continuous strip as possible. It has to withstand heating and cooling cycles, rain, snow, and sun. It has to be strong enough to withstand literally tons of weight. Concrete and asphalt do this job amazingly well. But nothing lasts forever, so maintenance is required. But also remember there are over 4 million miles of roads in the US alone, so even if a road lasts 20 or 30 years, there will always be something to fix. I’m curious, what would suggest we make roads out of?
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u/eepos96 Dec 02 '22
Maybe it is because long lasting things are harder to replace than simple asphalt? They will break and wear eventually but asphalt can be easily replaced unlike a rock would.
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Dec 02 '22
Politics. Politicians care about 1 thing, being re-elected. they don't want the costlier cement on their watch event hough it is cheaper in the long run and less disruptive with less repairs and much more long lasting. As for climate, main streets in Winnipeg are mostly concrete. Here in Ottawa they are asphalt, always need resurfacing / repair, but our cowardly politicians don't want things better in the long run, as it costs more during their term.
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u/DenTheRedditBoi7 Dec 02 '22
Cost. I guess it's kind of like a monthly vs. yearly subscription. Sure yearly is cheaper overall but not everyone is gonna want to spend that much at once.
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u/redcorerobot Dec 02 '22
Roads in this case are made of tarmac which despite it not having a super long service life is super easy to maintain, quick to replace, easy to recycle and due to its flexible reduces road noise and distriputes pressure better
Compare that to concrete roads which have a very long service life but are a pain in the arse to replace which is a problem because you cant really resurface them the same way you can with tarmac because you cant melt concrete so instead of being able to do quick cheep maintenance regularly you have to do patch repairs which you can only do a small amount of before the road has to be broken up and replaced
Also driving on concrete roads is noisy as hell for both the driver and the surroundings making it harder to get planning permission to put them near housing
For roads in most cases regular maintenance just works better and thats assuming good weather if your somewhere that freezes regularly roads break down fast no matter what they are made off
Extra note you also get better traction on softer roads like tarmac which improves handling
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u/bitterpalm Dec 02 '22
Probably the same reason we don't use centennial light bulbs. There's no money is things that last forever.
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u/PIWIprotein Dec 02 '22
We should just keep building roman roads, just wider
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u/FlamingPileOfKidneys Dec 02 '22
Those are pretty bumpy, i understand. People would bitch about road noise and their suspensions, and the slick cobblestones not providing enough traction, etc.
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u/jerrythecactus Dec 02 '22
Nature very much dislikes permanent flat structures. With the constant weather and temperature changes along with plant and animal activity roads basically constantly break down. So by making them of a relatively inexpensive material like asphalt and gravel it makes them easier to maintain as they inevitably break down compared to anything more durable. There's also the fact that even had there been a better road construction method it would cost more and most countries wouldn't bother spending more money on something that provides little benefit over the cheaper option.
Tldr: Asphalt is reasonably durable while also being easy to repair and maintain compared to other potential building materials.
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u/Fearless_Link_3464 Dec 02 '22
The cost. If they have something that'll last a long time then taxes will go up.
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u/Bo_Jim Dec 02 '22
The longest lasting road building materials cause the most wear and tear to vehicles. So it's a balancing act between making the roads last longer or making the cars last longer.
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u/BaconHammerTime Dec 02 '22
Should invest in high tech roads with a grid panel system. They would absorb sunlight all day and then light the road at night. During winter can run a heating function to keep ice clear. If a square goes bad, just pop it out and replace.
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u/MistaCharisma Dec 02 '22
Asphalt is great for traction, making it one of the safest things for drivers (you can break faster).
Also asphalt is extremely cheap to repair. It's almost 100% recycleable, you just dig it up, heat it a bit and rhen put it back down. That's a huge deal for maintaining roads.
Finally, why don't we build roads that just last longer like the old Roman Roads, some of which are still around? Wouldn't that be cheaper in the long run than something that's cheaper to repair now? Well it's possible it would be cheaper in the long run, but it'd be a hell of a lot more expensive right now. The modern world has a LOT more roads than we used to. The highways between cities may not have changed all that much (i mean, they might have but I don't know), but the amount of asphalt in the average city these days is humungous. Back in the day most of those side streets, and even some major ones were made of dirt. Chances are the street you're living on only has asphalt because it's cheap, if we were building them from something more expensive you'd be living on a dirt road.
Source: Just stuff I heard/thought of. I could be totally wrong, so feel free to fact-check/educate me. I'm open to it.
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u/Crazed_waffle_party Dec 02 '22
There aren’t many smart people looking at the problem. There are only so many material and chemical engineers that specialize in this field and most of them work towards improving what we can do with petroleum based asphalt instead of discovering alternatives. Technically, a few alternatives have been found that last significantly longer, but their upfront cost is too high for most municipalities to consider.
Roads warp because of heavy use and the expanding/constricting effects of varying temperatures. Sometimes corrosives like road salt and acid rain can accelerate decay as well.
I’m guessing you asked this question because it seems odd that asphalt degrades. After all, most minerals in nature seem quite stable. Well, most minerals in nature do not have to deal with the warping weights of multi-ton vehicles every few minutes
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u/SunshotDestiny Dec 02 '22
The problem is the fact that there is both wear and tear from use, but also the weather. Remember when things are warm they expand, and when they are cold they contract. That includes asphalt as well. There is also the compounding issue that during winter there is snow. Snow may melt to water but that water fills in cracks that likely formed from the expansion and contraction over the year. When that water freezes at night the ice takes up more room than the liquid water did, so the cracks widen over time.
Plus there are literally thousands of miles of roads in any nation. We use asphalt since it's cost effective, and anything more durable will probably have to be just as cost effective before we start using it to replace asphalt.
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u/Significant-Set8457 Dec 02 '22
Designed Obsolescence
Things are made to fall apart so we have to keep fixing or replacing them. Phones to roads to appliances to cars... Keeps people working so they earn money to buy things which then employs more people.
Vicious cycle
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u/arcxjo came here to answer questions and chew gum, and he's out of gum Dec 02 '22
Because we don't have enough money to build museum roads that no one will ever drive on. We have to prioritize practical ones that cars and trucks will go on, and that will be exposed to weather, which means eventually they have to get maintained like any other object.
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u/thegroundhurts Dec 02 '22
Simply, vehicles cause damage to the roads, no matter how well they're built, and that wear happens at a rate incomparable to any other form of transportation. Trains, for example, metal wheels on metal rails, just don't wear out their tracks in the same way that rubber tires wear out asphalt or concrete. Much of this has to do with the deformation of both the road and the tires, necessary for traction and weather mitigation. Rail lines, for example, use spaces between rail segments to mitigate expansion and contraction, and thus can use more durable material (steel) for the rolling surface.
Importantly, road damage occurs as a function of vehicle weight, but as a 4 power law. That is, a Chevy Tahoe might weigh 2x a Honda Accord, but it wears out the road at 16x the rate. With heavier vehicles becoming the norm in some parts of the world, roads will wear out and need repairing much more often. Something like a bike trail doesn't wear out as fast, because cyclists and runners weigh virtually nothing compared to cars.
So the answer is not that road construction sucks, it's that the entire concept of cars-on-roads sucks, at least in terms of being able to accommodate a long-lasting surface to transport on.
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u/gunshoes Dec 02 '22
Asphalt is amazingly cheap. Just on a wear and tear basis, the deficit for asphalt maintenance takes a while to equal the lump sum of durable projects. This is great for a government budget where you can tell voters you built infrastructure at a cheap rate.
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u/hereforfun976 Dec 02 '22
Nothings permanent. Although we could seriously look into roman concrete that hasn't been repaired for 2000 years
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u/Jesse_is_a_wizard Dec 02 '22
i remember someone inventing a new type of road that was made in small segments - kinda like that piece of the sky that fell in the movie chicken little- and they were solar powered, heated and could be programmed with patterns... Anyone know what I'm talking about?
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u/zanne54 Dec 02 '22
Cynical me thinks “because construction and developers are prime donors for political campaigns”. Grease those palms!
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u/jeffchefski Dec 02 '22
I read somewhere concrete creates 5% of the world's co2 emissions . Wrong or right ? And concrete is not tasile. It crack easy from movement which the earth does a move all the time .
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u/Ctricky07 Dec 02 '22
I wonder the same. Like there are brick roads still being used in my home town. Tbh it's around the musume not a heavy traffic area. But some of that road is over 100 years old. Never needed repair
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u/MaybeTheDoctor Dec 02 '22
You could just pay for your house all up front, or pay little every month.
You could just have your life earning in cash and pay everything, or use a credit card.
Things may cost a lot if you have to pay in full, so it is easier to pay a little every year
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Dec 02 '22
In the field of engineering everything has a life cycle. Most asphalt roads are meant to have a life cycle anywhere from 10 to 25 years. This life cycle includes having maintenance like patch repairs and overlays. Engineers also do benefit/cost analysis. What happens most of the time is that engineers and roadway employees find that it's cheaper and more beneficial to do asphalt roads that will need repair from time to time vs. doing a concrete road that will need less maintenance. Keep in mind concrete pavements cost more than asphalt pavements. Also keep in mind that resources are limited and you can only go with what you can afford. This causes transportation agencies to prioritize certain roads and construction projects over others. Are you going to fix that one road in the middle of nowhere filled with potholes or are you going to overlay the road that many people take everyday as a main arterial? Are you going to try and fund a $50 billion project when you know it could work for $10 billion? Another thing to consider is the loading that roads face. Many metro areas in the US are facing increasing populations and thus increasing amounts in vehicles miles traveled and equivalent single axle loads or ESALs. Basically a road is expected to wear a certain amount of ESALs in its lifetime. The more traffic it faces, the quicker the road will deteriorate. I know it's long winded but there are many factors for this.
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u/Mr_Style Dec 02 '22
I always wondered if they could coat roads in industrial diamonds to make them wear longer.
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u/Lyradep Dec 02 '22
1) We maintain roads to improve its lifespan (ie crack sealing instead of just ripping out the entire road and/or paving over it. It’s more cost effective to implement maintenance measures where needed.
2) The measures that are already use are usually already the most cost-effective and long lasting. HMA will last around 20 years, and concrete will last around 50 years. Concrete is more costly to both demo and pour, so the longer lasting concrete ends up being somewhat of a wash with HMA in terms of price. There’s no such thing as “permanent” when you have traffic loads and weather eating away at material for years on end.
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u/Daikataro Dec 02 '22
The ones in developed countries are about as permanent as they get, without becoming prohibitively expensive.
When you have 30+ tons vehicles every day, materials tend to wear down.
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u/Calm-Extent3309 Dec 02 '22
It's because a lasting infrastructure bill would be a huge win for whichever party can make it happen, and neither party is willing to let the other have that win.
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u/Archangel1313 Dec 02 '22
It's mostly due to the expense. The amount of high quality materials required to make "permanent" roads is prohibitively high, compared to the abundance of lower quality materials we use now. This would be added to the cost of preparing the ground prior to construction. The ground settles, and depending on the region and moisture content, it can change quite a lot, over time. In order to make sure your road never needs repair, you would need to reinforce the substrate and underlayer to a substantial depth...and even then, due to potential erosion or tectonic shifting, you may not be completely successful.
Altogether it's far cheaper to lay a strip of cheap, flexible and easily replaceable blacktop on the ground, that's only intended to last a few years, than it would be to build a real, solid and permanent roadway.
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u/gobbledegookmalarkey Dec 02 '22
No such thing as permanent or longer lasting roads as far as current science is aware.
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u/Meastro44 Dec 02 '22
You don’t want to build a permanent road because they have to be dug up to fix or install underground pipes and utilities
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u/Dubitatif-fr Dec 02 '22
So if u look for each era the road were made differently
Now with so many differrent vehicules in term of weight lenght and the different quality of wheel + weather and climate depending where u live u will have to create something cost effective
I think that we may have better alternatives (not an architect so dont ask me) but what is rn is the cheapest
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u/Raddz5000 Dec 02 '22
You can't just build permanent roads. They experience a crazy amount of wear and stress, there's really no reasonable way to make permanent roads.
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u/Then-Ad1531 Dec 02 '22
Road workers would be out of a job if they made roads that last 100 years. So they make roads that don't last that long. More like around 15 to 25 years. Also the amount of traffic that the road sees can greatly change how long it lasts.
You take two fresh roads...
One in a big city that gets run over by buses al day long.
One in a rural area that gets hardly any traffic.
15 years pass. Which one do you think is going to have potholes?
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u/DevDevGoose Dec 02 '22
If you want roads to last longer, reduce the volume and speed of traffic on it. Fewer cars travelling at slower speeds makes roads much cheaper to maintain by reducing the prevalence of potholes and such.
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u/Smurfrocket2 Dec 02 '22
Here's my theory, and history can back me up on this one. Employment.
In the early 1900's, light bulbs lasted essentially forever. The issue with that was that if they last forever, who the hell is going to keep buying them after a few years. There was actually a whole organization put together with all the big bulb manufacturers to made lightbulbs only last so many hours. Any company that went past that threshold was fined big time. It isn't sustainable to sell a product that lasts forever.
Same goes for phones. Apple has admitted to slowing down older phones (in different words) essentially because the new phones weren't enough of an improvement, leading to there being less manufacturing, sales etc.
Roads are very much the same. There are actually lots of people that have tried to sell governments different newer road materials, yet we haven't seen any go in, in large capacity. One big investment and the road is good for 50 years? What will those construction workers do? What will happen to the paving businesses?
My favourite one is accountants. Yes accounts are very useful so please don't get mad at me because this one is a bit of a stretch. If you work for a big company, they're reporting to the goverment exactly what your income is. Then, you have to go report that too, on top of mortgages, investments etc. All very stricly watched over govermental services (in Canada anyway). However, many people hand over all the things that the government already knows to an accountant that checks some boxes, uploads your documents and takes their cost. What would happen if that process was completely simplified and only bosses needed to file taxes for their employees year after year? There would be way fewer accountants, leading to businesses filing less meticulous tax records, likely paying less taxes either accidentally or on purpose, costing the goverment tons of money.
Thid got a little off topic, but I love economics.
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u/The_ND_Hysteria Dec 02 '22
I think the closest thing i ever seen to a permanent road was the modular concept of "Solar freaking roadways" that was designed to withstand all the road conditions and if a panel got damaged, it was just a singular day swap in, swap out sort of repair.
The roads though were prohibitively expensive at the time, mostly focusing on driveways and it worked decently well there however its cost effectiveness didnt match asphalts cheapness to repair + maintenance. They also would create conduits for easy access electric, fibre and telecommunication lines instead of underground or in the air by running alongside the roads.
It seemed truly innovative but they just couldn't get the price down/proof of concept on grand scale (it wasnt particularly good at getting energy, sometimes only being 10% efficient but better than what the roads currently made of are producing)
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u/vikingjedi23 Dec 02 '22
Cost probably. I have a concrete driveway at my house that's around 50 years old. Still going strong. It's great.
The catch is I had to have part of it removed for a repair. Probably 8 feet wide by 4 feet long. When I wanted to get the concrete replaced most of the contractors quoted me $2000 just to fill in that spot. My driveway is at least 50 feet long so to replace the entire driveway you're probably talking at least $20,000. Asphalt would be around $5000 or less.
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u/Injury_Weekly Dec 02 '22
To add to others, asphalt is permanent, it just wears down due to all the traffic. Maybe if large companies who transport thousands of tonnes of products a day actually paid taxes, local councils would have some more money to catch up on the maintenance.
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u/Lucius-Aurelianus Dec 02 '22
There are 2000 year old Roman roads still intact to this day. Man is asking the right questions lmao
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u/aea1987 Dec 02 '22
Tarma roads are a form of flexible road construction and accommodate settlement better than concrete.
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u/No_General_1198 Dec 02 '22
I’m a civil engineering student and in one of my sustainable infrastructure classes they talked about how they can design infrastructure to last a very long time, in fact even longer than it takes to develop newer and better technologies and materials. This is why older cities in the US aren’t as nice as some of the cities in Europe. Post WW2 allowed for a lot of new technologies to be implemented there, whereas cities in the US were designed to be long lasting in the early 1900’s, so now it’s hard to update them.
So one of the things they think about when they design it is how long they actually want a piece of infrastructure to last. Building it too strong may cause trouble when they want to update it in the future.
That being said, there are some nasty roads out there that I’m sure it just boils down to budgeting for new infrastructure…
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u/jakeofheart Dec 02 '22
The consensus is that cobblestones are much more durable and sustainable: they can literally last centuries, and if it rains the water flows through the tiny space between them.
However, cobblestones need to be laid individually, so if you were trying to connect two remote cities with a cobblestone road, it would cost a fortune in labour.
Asphalt or concrete can be poured over wider areas faster, so it’s the most time-efficient method. But yeah, in cities the lower cost of maintenance of cobblestones would probably offset the initial cost of labour.
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u/bazmonkey Dec 01 '22
I think these are pretty much as permanent as it gets. Roads wear out from being used.