Any experience with permeable driveway materials?

[Bird In Hand]

Our asphalt driveway is coming up on end-of-life, around 20 years.  It will probably survive another 1-2 years, but no more.  A short-lived top-coat of asphalt will cost around $5k.  A full tear-out and repave is probably going to be around $10k.

I like that asphalt is smooth (when new), but that's about it.  It's ecologically suspect, has a short lifespan, causes water/pollutant runoff issues, and needs frequent maintenance (seal-coating, a couple hundred $$ every couple years) with chemicals that are also not healthy for humans, animals, or the local environment.

I was researching budget-friendly alternatives that are also more ecologically friendly.  Gravel was mentioned, and I'd consider that -- though the ~yearly re-grading due to snow plowing is going to be a pain.  I'm not so sure about snowblowing over gravel either.

Another option was a kind of permeable paver.  Basically a honeycomb grid of recycled plastic that you fill with gravel/stone, or even grass.  Here's one example of many similar products: Truegrid Paver (no affiliation).

I'm wondering if any Mustachians have experience with these types of permeable pavers.  Mostly I'm interested in installation cost vs asphalt, lifespan, required maintenance, and suitability for cold/snowy climates.  It also has to be able to stand up to the occasional fuel delivery truck.

[bigblock440]

If you're considering gravel, the most cost effective is to just let it revert to gravel naturally.

[FIDeckard]

I have been thinking the exact same thoughts with respect to our asphalt driveway. In our case, we have a detached 3-car garage that the driveway leads to in the back, and that puts our lot way over our town's allowed non-permeable surface allotment. So, in effect, we cannot put in anything like a deck or patio. And we don't have much of a yard - the driveway splits the yard we do have into two small parts on either side.

Have you looked at all into something like artificial turf? I would think that would have to have some sort of drainage solution built underneath it, but maybe an option. We've got the same issue with snow and I doubt a gravel surface, even leveled, would be a good thing to run a snow thrower over, unless you had a nice solid ice sheet layer on top of it.

Will be following this thread looking for the same advice!

[Bird In Hand]

If you're considering gravel, the most cost effective is to just let it revert to gravel naturally.

Interesting!  That had not occurred to me.  We had a rather ancient and neglected asphalt driveway when I was a kid, and I recall large cracks, potholes, and heaving sections (due to freeze/thaw cycles).  I suppose with a little elbow grease one could add some additional gravel to cracks/potholes as they appear, and use a sledgehammer or something similar to even out uneven sections due to heaves.

This sounds like a very...redneck approach, so naturally I'm interested.

[LostGirl]

You talk about snow plowing, if its an actual plow then I would not recommend permeable pavers. The turfblok kind will get torn up by the plow, and permeable concrete or other will get clogged with debris and not percolate.

[Bird In Hand]

You talk about snow plowing, if its an actual plow then I would not recommend permeable pavers. The turfblok kind will get torn up by the plow, and permeable concrete or other will get clogged with debris and not percolate.

I don't mean an actual plow -- we use a walk-behind snow thrower 99% of the time.  Once or twice in the last decade we hired someone with a plow blade on their pickup to push the snow for us when our snow thrower was broken.

[SunnyDays]

Why wouldn’t you just put in a concrete driveway?  It will last at least 30 years, even in a cold climate.  It might be more expensive at first, but there is no maintenance involved and the rubble it will eventually become can be reused if your area offers that.

[AccidentialMustache]

My folks had a gravel drive when I was a kid. They did not and have not ever used a snowblower on it. By hand, by shovel. You get strong I guess? I'd imagine the larger rocks sticking up would dent up your spiral blades horribly.

Gravel also is excellent at icing up if you have any freeze-thaw mechanics. Chipping the ice out, anchored by/to rocks sucks.

There are options: https://www.mortonarb.org/files/MainParkingLot.pdf

[TheFrenchCat]

We have gravel and it's been an adjustment. We shovel by hand and I had to learn to not spin out on it. If we get a lot of snow (6+ inches), my father-in-law uses a snowblower on his, raised so it doesn't touch the ground to move the top level off.  Then he does the rest by hand. 

I don't think you need to regrade every year.  Ours was done 2 years ago and it's barely changed, and that's with a ton of run off down it.  But my husband's uncle owns a bulldozer (and the house we rent), so he just does it when needed.  I don't know if there's another way to do that. 

I don't really like it, but asphalt's so expensive I'm adjusting to it instead. 

[Bird In Hand]

Why wouldn’t you just put in a concrete driveway?  It will last at least 30 years, even in a cold climate.  It might be more expensive at first, but there is no maintenance involved and the rubble it will eventually become can be reused if your area offers that.

Nobody uses concrete for driveways where I live, and I imagine that cost is the main reason.  Our driveway is close to 200' long, and that's typical in this area.  If asphalt costs $5k-$10k, I would expect concrete to run $10k-$15k or more.

We also have issues with runoff ponding at the low section near the street, which is another reason I was intrigued by the permeable pavers.

[Freedom2016]

Our driveway is about 700' long, gravel. We have plow service in the winter and as long as the blade is kept a little above the ground, it's fine.

We have been doing some re-grading and adding more gravel each of the two summers we've lived here so far. When we costed out doing that for 20 years versus paving or asphalt, it came in way more cost effective. The driveway also goes through a wetland portion of our property and gravel is a far more ecological solution than paving/asphalt (for which we would have to pull permits).

[Fishindude]

A lot of asphalt residential driveways get installed over a "too soft" base material and / or the asphalt installed is too thin so they don't last very long.   Oil or gas dripping on asphalt will ruin it, as will driving heavy trucks or equipment on it.   Cranking your tires hard to turn in the same area time after time will eventually wear that area out also.   Concrete wears and lasts much longer but typically costs more also.

The problem with a permeable driveway like suggested or gravel is that every time you walk into the house or garage, or get into your car you tend to bring a little bit of the driveway in with you; little pieces of dirt or gravel cling to your shoes and it goes where you go.   You can keep your house, garage and vehicles much cleaner with a hard surface driveway such as asphalt or concrete.

If you are in a snow area hard surfaces also clean up and the ice goes away much easier.   Raking the gravel out of the lawn from snow plowing every spring used to be a tradition here.

Gravel and the permeable drive mentioned will also have weed control issues and the gravel will require periodic regrading, patching pot holes, etc.

Paving our driveway was one of the better things we ever did in regards to keeping the place neat and clean.   Grand kids like it too for their bikes, scooters and sidewalk chalk.   I don't mind paying $700 every couple years for a re-seal job to keep it in good shape.

[bigblock440]

If you're considering gravel, the most cost effective is to just let it revert to gravel naturally.

Interesting!  That had not occurred to me.  We had a rather ancient and neglected asphalt driveway when I was a kid, and I recall large cracks, potholes, and heaving sections (due to freeze/thaw cycles).  I suppose with a little elbow grease one could add some additional gravel to cracks/potholes as they appear, and use a sledgehammer or something similar to even out uneven sections due to heaves.

This sounds like a very...redneck approach, so naturally I'm interested.

Most time-efficient too.

I also know a few people who used millings to do their driveways, seems like a combination of paving and gravel.  It's cheap because it's waste material from road/parking lot repair, and it packs down very well, especially with heat.  Just dump, spread, and roll.  It also seems like it's fairly permeable, but I don't know that for sure.

[joleran]

My understanding is that asphalt can be re-melted pretty much at will.  Have you looked into any services that will basically re-do the driveway in place?

[BussoV6]

When I lived in Germany, we used a product called Elastopave. It looks a bit like asphalt, but is porous. Not sure if this would be available in your area.

[Alternatepriorities]

After 2 years of shoveling and snow blowing a large gravel driveway we are upgrading to asphalt this year. I still have mixed feelings about it, mostly for the reasons you mentioned. However I think this summer will be the cheapest time to do it. My neighbor has been looking to do his for a few years now and told me his quote was a couple thousand cheaper than last time he got one. Our driveway is at least 3-4 times the size of the one I had paved near bye in 2012. The total is less than 2x what it cost to do that one. And So far it looks like this company is doing a better job as well.

[gillstone]

We had to get rid of our concrete driveway as it was sloping water towards the house.  We are still considering adding a detached garage so we didn't want to put in something permanent and opted for gravel.  I've had gravel for two winters so far and its not bad.  You can shovel and snowblow if you aren't aiming for a perfectly clean surface.  It doesn't ice up since our freeze/thaw cycle means any thaw drains into the ground.   

Weed control isn't hard.  You can manage it with boiling water or a 3:1 water to salt mixture applied directly.

[Alternatepriorities]

Weed control isn't hard.  You can manage it with boiling water or a 3:1 water to salt mixture applied directly.

Thanks!
I hadn't thought of using salt for weed control. I don't want to use herbicides, but salt seems reasonable... I'll need to try that around our rocks...

[Sanitary Stache]

I had asphalt that was falling apart and now have gravel.  I couldn't break the asphalt into small enough pieces to rake smooth with the grade rake.  I paid for the asphalt to be removed and for the gravel to be delivered.  Then I spent three days shoveling, raking, and compacting gravel.  I don't have much of a driveway though, maybe 30 feet long. I would not have made it past three days though, so paying for equipment to grade and compact the gravel would have happened if I was doing this for 200 feet.
The gravel is much dirtier for the house than the asphalt was.  Plowing was not an issue last year, but I suck at shoveling, so had a pretty solid layer of ice before calling the plow.
Have you considered significantly reducing your driveway and parking farther from the house?
Our current plan is to install brick over the gravel, once I am fully satisfied the gravel base isn't going anywhere, and it looks good so far.  We want to use some of those bricks that have holes in them to let some weeds give our driveway a little green and, I suppose, infiltrate some water. I guess.  I find it hard to get excited for storm water treatment these days.

[Sibley]

The alleys in my town were repaved with permeable asphalt (that's what it looks like at least) about 5 years ago I believe. It's not holding up as well as regular asphalt, and it is getting weeds in it where there's problems. Most notable, there's a couple spots on my block that have some pretty extreme potholes forming. My guess is a combo of poor prep and extra wear on those spots.

[nereo]

Ptf

[AMandM]

I recently got quotes to replace our driveway (750 sq ft).
Concrete quote was $14300
Permeable pavers quote was $18750.

It is possible that the permeable quote is artificially inflated, because our county has a rebate program if you replace a non-permeable driveway with a permeable one. The contractor said that the cost is high because they have to dig down deep to install the layers of multiple sizes of gravel that provide drainage under the pavers. Apparently you can't just scrape off the old driveway surface and slap permeable pavers on top of the dirt. :-P

[Alternatepriorities]

I recently got quotes to replace our driveway (750 sq ft).
Concrete quote was $14300
Permeable pavers quote was $18750.

Wow! The 3600 sq ft of asphalt we just did today only cost about $9k and that included the extra 4 hours of dirt work they did.

[nereo]

Surprised no one has mentioned the high environmental cost of concrete yet.  Typically among the most polluting of building materials.

[Alternatepriorities]

Surprised no one has mentioned the high environmental cost of concrete yet.  Typically among the most polluting of building materials.

Do you have any data on the environmental impact of concrete vs asphalt that wasn't sponsored by a company that makes one or the other? I'm mostly just curious.

[nereo]

Surprised no one has mentioned the high environmental cost of concrete yet.  Typically among the most polluting of building materials.

Do you have any data on the environmental impact of concrete vs asphalt that wasn't sponsored by a company that makes one or the other? I'm mostly just curious.

The brief answer here is: "it depends".  Traditional cement used to make concrete has one of the greatest carbon footprints of any building material, and if that is reinforced with traditional steel rebar you get another material with a high environmental cost. 
Producing cement involves heating calcuium carbonate (CaCO3) - typically as limestone - to very high temperatures, which 1) takes energy and 2) releases massive amounts of CO2.  The equation is CaCO3 (Calcium Carbonate) -> CaO (lime) + CO2 (Carbon dioxide).

To get the limestone in the first place involves mining (energy intensive), then heating in a furnace (more energy), followed by the chemical release of CO2. Because cement factories are always located next to limestone deposits which are not necessarily anywhere near their end-use, transportation in some locales can have another big impact... just depends on where you live. Some processed lime will travel a couple of miles, others several hundred.

Most estimates put the production of a each ton of cement at releasing almost equal amounts of CO2 (~90%).  Globally cement production contributes roughly 8% of greenhouse gases.  It's gynormous. The IPCC reports that the cement industry releases 2.2 Billion Metric Tons per year

Because it's such a big contributor to greenhouse gases you can find reams of information.  But here's a few places to start:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiK7OSXgL_rAhVLbs0KHRyACBEQFjABegQIChAD&url=https%3A%2F%2Fwww.ipcc-nggip.iges.or.jp%2Fpublic%2Fgp%2Fbgp%2F3_1_Cement_Production.pdf&usg=AOvVaw1Q3sE8dPJKkYgyZhI-Awth
https://en.wikipedia.org/wiki/Cement#Environmental_impacts

But of course there are ways to mitigate to some degree the carbon footprint in concrete.  Fly ash from coal power plants (where available) can replace a large portion of the cement used concrete, and glass fibers can be substituted for steel rebar or wire mesh but give similar tensile strength to the final pad.  There are also some 'Eco-crete' versions which re-absorb CO2, during the hardening process.


tl-dr; if you want to reduce the environmental impact of a structure, reduce the amount of concrete wherever it is practical to do so, and/or find an Eco-Crete or fly-ash version to sustitute.

[Fishindude]

The environmental debate of concrete being worse than asphalt is just silly.

Asphalt also requires mining to obtain the aggregate, plus oil extraction to obtain the binding material, then a nasty gas fired cooking process, trucking, spraying binder oil down on the surface before placement, then placement with a bunch of diesel guzzling equipment and rollers, and the whole operation is real stinky till it hardens up.

Both products require some processes that affect the environment.  Done properly concrete can be a one time, lifetime lasting installation while an asphalt drive requires continual upkeep and maintenance and still will require replacement in 20-30 years at best.

Not pitching one over the other, I've got an asphalt driveway.   I just think the environmental argument between these two options is nuts and shouldn't be considered too much in the decision.

[bacchi]

But of course there are ways to mitigate to some degree the carbon footprint in concrete.  Fly ash from coal power plants (where available) can replace a large portion of the cement used concrete, and glass fibers can be substituted for steel rebar or wire mesh but give similar tensile strength to the final pad.  There are also some 'Eco-crete' versions which re-absorb CO2, during the hardening process.

I did ask for fly ash but I never even considered non-metal rebar. It's also used for grounding so it can't be a 100% replacement for a house, though.

[Alternatepriorities]

The environmental debate of concrete being worse than asphalt is just silly.

Asphalt also requires mining to obtain the aggregate, plus oil extraction to obtain the binding material, then a nasty gas fired cooking process, trucking, spraying binder oil down on the surface before placement, then placement with a bunch of diesel guzzling equipment and rollers, and the whole operation is real stinky till it hardens up.

Both products require some processes that affect the environment.  Done properly concrete can be a one time, lifetime lasting installation while an asphalt drive requires continual upkeep and maintenance and still will require replacement in 20-30 years at best.

Not pitching one over the other, I've got an asphalt driveway.   I just think the environmental argument between these two options is nuts and shouldn't be considered too much in the decision.

My understanding is that asphalt is nearly all recyclable. Grind it up, heat it, add a bit more tar and lay it back down. Concrete can't be recycled as concrete but is sometimes broken up and reused as crushed gravel fill. It seems like having a bunch of steel in the middle of the concrete would make it even harder to recycle. In my location both concrete and asphalt fall apart eventually though concrete does last longer.

I poured a pad myself last summer and then had the driveway done in asphalt this summer. Based on the cost and area of each, having someone else do the work with asphalt was at most 1/3 what it would have cost pour concrete doing all my own work. As i highly doubt we will own this house in 20 years I think the asphalt was the better choice for this project. Admittedly the most Mustachian thing would have been to leave it gravel. 

[Alternatepriorities]

But of course there are ways to mitigate to some degree the carbon footprint in concrete.  Fly ash from coal power plants (where available) can replace a large portion of the cement used concrete, and glass fibers can be substituted for steel rebar or wire mesh but give similar tensile strength to the final pad.  There are also some 'Eco-crete' versions which re-absorb CO2, during the hardening process.

I did ask for fly ash but I never even considered non-metal rebar. It's also used for grounding so it can't be a 100% replacement for a house, though.

On the slab I did last year I used some wire mesh as well as fiber on the recommendation of my father who is a retired construction contractor. "Better to spend a little more now and never need to replace it." Unfortunately my one mistake left a low spot at the bottom of the stairs which is definitely the worst place for it to have been.

[Fishindude]

My understanding is that asphalt is nearly all recyclable. Grind it up, heat it, add a bit more tar and lay it back down. Concrete can't be recycled as concrete but is sometimes broken up and reused as crushed gravel fill. It seems like having a bunch of steel in the middle of the concrete would make it even harder to recycle. In my location both concrete and asphalt fall apart eventually though concrete does last longer.

Concrete is also 100% recyclable.   They crush it up, extract the steel and recycle it, then utilize the crushed aggregate as engineered fill material instead of trucking in mined limestone and / or mix the crushed aggregate with Portland cement, etc. and make new concrete.

The fibermesh is a "plastic" material so it comes from oil extraction.  Pick your poison regarding which is more environmentally friendly, oil extraction or steel milling.
Also, the fibermesh is junk as a reinforcement compared to steel.  Only time I would use it would be for a very thin slab where thickness did not allow steel reinforcement.

Nearly all ready mix concrete has some fly ash and other non cement additives in it these days, and unless you are an engineer or large user specifying an exact mix, you won't have much say on the "recipe" you purchase.   The only things you will specify are the slump, the PSI strength mix and if you want air entrainment or not.
 

[joe189man]

something like this may work for you
https://www.truegridpaver.com/complete-guide-permeable-paving-systems%EF%BB%BF/

your low spot with drainage issues may need a culvert

[yachi]

My understanding is that asphalt is nearly all recyclable. Grind it up, heat it, add a bit more tar and lay it back down. Concrete can't be recycled as concrete but is sometimes broken up and reused as crushed gravel fill. It seems like having a bunch of steel in the middle of the concrete would make it even harder to recycle. In my location both concrete and asphalt fall apart eventually though concrete does last longer.

I poured a pad myself last summer and then had the driveway done in asphalt this summer. Based on the cost and area of each, having someone else do the work with asphalt was at most 1/3 what it would have cost pour concrete doing all my own work. As i highly doubt we will own this house in 20 years I think the asphalt was the better choice for this project. Admittedly the most Mustachian thing would have been to leave it gravel.

Interesting discussion we have going here.  Asphalt is very much more recyclable than concrete.  I've seen some say it's the world's most recycled product.  You're right:  heat it up, and combine it with more tar it's new asphalt. 
Concrete can be crushed and used as stone for construction entrances, but it has very limited applications:
Some government agencies consider it unnatural fill that cannot be used on construction sites
It cannot be used as replacement for crushed stone under roadways, under foundations, sidewalks, etc.
Reinforcing steel seems to be missing in it, either because the site doing the crushing doesn't accept it that way, or because it's removed.  I have, however found Pencil-diameter fiberglass rods in it -- bad news for construction site entrances.

I'm not sure if the strength of crushed concrete is the concern for it's limited use or if it's remnants of times when on-site structures would be broken up and buried on site.

[Alternatepriorities]

My understanding is that asphalt is nearly all recyclable. Grind it up, heat it, add a bit more tar and lay it back down. Concrete can't be recycled as concrete but is sometimes broken up and reused as crushed gravel fill. It seems like having a bunch of steel in the middle of the concrete would make it even harder to recycle. In my location both concrete and asphalt fall apart eventually though concrete does last longer.

Concrete is also 100% recyclable.   They crush it up, extract the steel and recycle it, then utilize the crushed aggregate as engineered fill material instead of trucking in mined limestone and / or mix the crushed aggregate with Portland cement, etc. and make new concrete.

The fibermesh is a "plastic" material so it comes from oil extraction.  Pick your poison regarding which is more environmentally friendly, oil extraction or steel milling.
Also, the fibermesh is junk as a reinforcement compared to steel.  Only time I would use it would be for a very thin slab where thickness did not allow steel reinforcement.

Nearly all ready mix concrete has some fly ash and other non cement additives in it these days, and unless you are an engineer or large user specifying an exact mix, you won't have much say on the "recipe" you purchase.   The only things you will specify are the slump, the PSI strength mix and if you want air entrainment or not.
 

I was able to request the number of sacks of cement per yard (related to PSI strength) and also to request glass fibers in the mix which helps prevent micro cracks. I did use steel mesh. it's and outdoor slab, and has now survived one AK winter crack free.

[yachi]

What you're trying to do with permeable driveway materials isn't primarily reducing your use of high-carbon cost construction materials.  You're trying to reduce stormwater runoff.  Just a few weeks ago I drove home during a heavy rain, and every gravel driveway had a concentrated stream of mud coming off of it onto the road.  I'm sure these streams also contained the same oil, grease and antifreeze drippings you would find on runoff from a concrete or asphalt driveway.  But they also contained soil that's being washed away and isn't helpful to creeks.
When you drive over the same patch of dirt and stones over and over, you compact it to where the water isn't going to seep into the ground.  Your permeable driveway materials are trying to prevent the soil from being compacted to allow water to seep into the soil instead of running off of it.
You can also design your driveway with features like a slope toward a stormwater retention pond or drains to underground stormwater infiltration to keep the stormwater out of creeks and reduce your impacts.  These solutions depend on the particular layout of your property. 

[joleran]

Just to toss this out there - everything is recyclable, it's just a matter of cost.

[Fishindude]

Concrete can be crushed and used as stone for construction entrances, but it has very limited applications:
Some government agencies consider it unnatural fill that cannot be used on construction sites
It cannot be used as replacement for crushed stone under roadways, under foundations, sidewalks, etc.

Reinforcing steel seems to be missing in it, either because the site doing the crushing doesn't accept it that way, or because it's removed.  I have, however found Pencil-diameter fiberglass rods in it -- bad news for construction site entrances.

This is just untrue. 
Crushed concrete is frequently used for fill material under roadways, building slabs, around foundations, under driveways, you name it, it's a good product.
You extract the steel reinforcement from it and recycle the steel.  It is true that some small pieces of steel occasionally get missed in the recycling process and wind up in the crushed material, so it's best not to use it as finished driveway material, as a stray piece of wire could lead to flat tires.  In these cases, you'd be advised to "top it" off with a layer of clean virgin aggregate.   

I've crushed and re-used a lot of it.
Makes a hell of a lot more sense than trucking it off and burying it in a landfill somewhere.

[yachi]

This is just untrue. 
Crushed concrete is frequently used for fill material under roadways, building slabs, around foundations, under driveways, you name it, it's a good product.
You extract the steel reinforcement from it and recycle the steel.  It is true that some small pieces of steel occasionally get missed in the recycling process and wind up in the crushed material, so it's best not to use it as finished driveway material, as a stray piece of wire could lead to flat tires.  In these cases, you'd be advised to "top it" off with a layer of clean virgin aggregate.   

I've crushed and re-used a lot of it.
Makes a hell of a lot more sense than trucking it off and burying it in a landfill somewhere.

You know, I stand corrected.  It does look widely used.  I've not been allowed to use it on many utility jobs in Maryland, but maybe my engineers were just difficult.  Here's one survey study showing widespread use:
http://www.acpa.org/wp-content/uploads/2018/03/RCA_US_usage_summary_w_cvr.pdf

[nereo]

The environmental debate of concrete being worse than asphalt is just silly.

Asphalt also requires mining to obtain the aggregate, plus oil extraction to obtain the binding material, then a nasty gas fired cooking process, trucking, spraying binder oil down on the surface before placement, then placement with a bunch of diesel guzzling equipment and rollers, and the whole operation is real stinky till it hardens up.

Both products require some processes that affect the environment.  Done properly concrete can be a one time, lifetime lasting installation while an asphalt drive requires continual upkeep and maintenance and still will require replacement in 20-30 years at best.

As I explained above, concrete has a much, much higher carbon footprint than asphalt, even accounting for it's increased longevity.  At the heart of why is how it's formed.  Cement is formed from limestone (CaCO3) which must be heated to produce lime (CaO), the principle component of portland cement (plus water).  Doing so releases boatloads of CO2 (a greenhouse gas).  how much?  well CaCO3 has a molecular weight of 100.1; CaO has a molecular weight of 44.1; 
Ergo, every metric ton of limestone used to make cement releases 441 kg of CO2.  Then there's the energy required to cook the limestone and transport it.  In the each metric ton of concrete releases about 900kg of CO2 into the atmosphere

As you mentioned, asphalt also carries its own sizable costs, but it's roughly 150kg per ton. 

So no, it's not equal, not by a  longshot.

[MayDay]

The environmental debate of concrete being worse than asphalt is just silly.

Asphalt also requires mining to obtain the aggregate, plus oil extraction to obtain the binding material, then a nasty gas fired cooking process, trucking, spraying binder oil down on the surface before placement, then placement with a bunch of diesel guzzling equipment and rollers, and the whole operation is real stinky till it hardens up.

Both products require some processes that affect the environment.  Done properly concrete can be a one time, lifetime lasting installation while an asphalt drive requires continual upkeep and maintenance and still will require replacement in 20-30 years at best.

As I explained above, concrete has a much, much higher carbon footprint than asphalt, even accounting for it's increased longevity.  At the heart of why is how it's formed.  Cement is formed from limestone (CaCO3) which must be heated to produce lime (CaO), the principle component of portland cement (plus water).  Doing so releases boatloads of CO2 (a greenhouse gas).  how much?  well CaCO3 has a molecular weight of 100.1; CaO has a molecular weight of 44.1; 
Ergo, every metric ton of limestone used to make cement releases 441 kg of CO2.  Then there's the energy required to cook the limestone and transport it.  In the each metric ton of concrete releases about 900kg of CO2 into the atmosphere

As you mentioned, asphalt also carries its own sizable costs, but it's roughly 150kg per ton. 

So no, it's not equal, not by a  longshot.

It would depend on the life though.

Even at those numbers, in MN my concrete driveway is 70 years old and not close to replacement. I've only had an asphalt driveway once but it looked like shit after 10 years, probably would have made it to 20 before totally replacing. Obviously that is one anecdote but it seems like from what I see concrete has the potential to last a really long time.

[nereo]

Yes, one must certainly consider all factors, and longevity is one of the big ones.
Concrete has an enormous carbon footprint during intial construction, but can last far longer than most materials. A properly installed and maintained asphalt driveway should last two decades.

[Sanitary Stache]

It is called a Life Cycle Cost Analysis.  And it can apply environmental costs.  One reason why we need carbon pricing.

[Alternatepriorities]

One of the difficulties with trying to do a life cycle analysis on something like concrete is the life expectancy of it. Can any of us really make a solid guess at what the world will look like in 70 years? Are driveways even going to be a thing?

[nereo]

One of the difficulties with trying to do a life cycle analysis on something like concrete is the life expectancy of it. Can any of us really make a solid guess at what the world will look like in 70 years? Are driveways even going to be a thing?

That's one reason why the upfront carbon costs in any construction project are considered so important; the distant future is too unknown.  An addition, construction work, natural disaster (e.g. earthquake) or simply an aesthetic/lifestyle change and render the maximum likely lifespan moot.  After all, the subject of this thread focuses on "permeable materials".  If a durable, permeable and relatively eco-friendly product comes to market anytime in the next decade or two I'd be extremely likely to dig up whatever driveway I'll have by then.

FWIW Angie's List suggests the typical lifespan of a concrete driveway to be around 30 years, not 70, though it depends on usage, upkeep and environment.

[Fishindude]

That's one reason why the upfront carbon costs in any construction project are considered so important; the distant future is too unknown.  An addition, construction work, natural disaster (e.g. earthquake) or simply an aesthetic/lifestyle change and render the maximum likely lifespan moot.  After all, the subject of this thread focuses on "permeable materials".  If a durable, permeable and relatively eco-friendly product comes to market anytime in the next decade or two I'd be extremely likely to dig up whatever driveway I'll have by then.

FWIW Angie's List suggests the typical lifespan of a concrete driveway to be around 30 years, not 70, though it depends on usage, upkeep and environment.

I've built hundreds of large industrial commercial construction projects and the "upfront carbon costs" never came up for discussion in anything we ever built, so it's apparently not all that important to those of us involved with actually building things.   There was a hot trend going several years ago where there was a big push to build things to LEED standards "Leadership in Energy & Environmental Design".   Architects were pushing it, there were rewards programs with recognition, a LEED scoring, system, etc.   That turned out to be nothing more than a barrier to keep some players (non LEED qualified) out of the game and ran the cost of construction up so it has mostly died off in popularity.   One LEED project we did, the architect had us put in expensive bike racks at an industrial office complex for LEED points.   Never saw a bike in that facility ever, but they got points for it and a plaque for their wall.

If you truly want to be environmentally friendly, you build things right and you build things one time, and you use recyclable materials whenever possible.   This makes a very strong case for concrete drives.   The drives at my shop are 40 years old and still in great shape, no reason they won't last another 20+ years.   Same could be said for metal roofs.   We've got 50+ year old metal roofs still in service and performing well, while shingles and rubber roofs need replaced every 15-20 years.

If someone really wants a permeable driveway (which I'm not sure I'd recommend), there are a couple options.   They make some precast concrete "waffle" shaped paver stones you can lay down as a driveway surface, then the voids get filled with soil and seeded with grass.   This allow you to drive on a relatively solid surface that water can get through.   The grass requires some upkeep and those waffle shaped pavers are likely to break up under heavy loads and won't last as long as a slab.  This does look real nice.
Another option is "permeable concrete".  This is a porous ready mix concrete that allows water to pass through it and get away.  It has it's own set of problems too.  The fact that it's porous means you have to keep it real clean so the pores don't clog and it quits working.   The fact that it can hold water would also make it more subject to breaking up in extreme cold and freeze / thaw cycles.

[Bird In Hand]

If someone really wants a permeable driveway (which I'm not sure I'd recommend), there are a couple options.   They make some precast concrete "waffle" shaped paver stones you can lay down as a driveway surface, then the voids get filled with soil and seeded with grass.   This allow you to drive on a relatively solid surface that water can get through.   The grass requires some upkeep and those waffle shaped pavers are likely to break up under heavy loads and won't last as long as a slab.  This does look real nice.

Any thoughts on the option I mentioned in the OP?  To wit:

Another option was a kind of permeable paver.  Basically a honeycomb grid of recycled plastic that you fill with gravel/stone, or even grass.  Here's one example of many similar products: Truegrid Paver (no affiliation).

I would probably go with the gravel-filled ones; the grass-filled ones are an interesting novelty, but would soon be filled with crabgrass and I'm not really interested in that kind of maintenance commitment.  I'm also somewhat concerned about the ability of the plastic to stand up to heavy loads, like a fuel delivery truck or septic tank truck.

[Radagast]

If someone really wants a permeable driveway (which I'm not sure I'd recommend), there are a couple options.   They make some precast concrete "waffle" shaped paver stones you can lay down as a driveway surface, then the voids get filled with soil and seeded with grass.   This allow you to drive on a relatively solid surface that water can get through.   The grass requires some upkeep and those waffle shaped pavers are likely to break up under heavy loads and won't last as long as a slab.  This does look real nice.

Any thoughts on the option I mentioned in the OP?  To wit:

Another option was a kind of permeable paver.  Basically a honeycomb grid of recycled plastic that you fill with gravel/stone, or even grass.  Here's one example of many similar products: Truegrid Paver (no affiliation).

I would probably go with the gravel-filled ones; the grass-filled ones are an interesting novelty, but would soon be filled with crabgrass and I'm not really interested in that kind of maintenance commitment.  I'm also somewhat concerned about the ability of the plastic to stand up to heavy loads, like a fuel delivery truck or septic tank truck.

I previously lived in a house and neighborhood built in the 1930’s. A common theme of the era was that people didn’t have much money. One of the coolest things was that many of the garages had 2-track driveways, I assume to save concrete. They had two narrow strips of concrete perhaps a snow shovel width across in the wheel tracks that led to the correct parking position, with regular yard grass in between and to each side. Those driveways were perfectly straight and not more than 50 feet long though, it might not work as well for your situation. But it might look really neat if you did it. Google image search two track concrete driveway. You could make the concrete 6” thick with regular expansion/contraction joints (say every 2x width) and fibers, no steel, and it should be crazy durable and not too expensive. Random internet search result: https://www.gardenista.com/posts/hardscaping-101-ribbon-driveways/

I have come across some similar plastic permeable gravel holders, but never quite used them. I would suggest that the gravel is bearing the weight of the vehicle, and the plastic is just confining it. You would want to keep the gravel topped off or else the plastic might indeed get crushed. It really isn’t much different from a plain gravel driveway. To make it drain better you will want to extend the gravel about 4” below the grid, with a layer of geofabric on bottom to separate the finer soil underneath. There are other competing products which you can research, or maybe one which is readily available in your area.