Truck driver. Not quibbling, just adding nuance.
For your typical 40t scenario, allowed max weights are:
12,00 pounds on the front steering axle. It has one tire at each end.
34,000 pounds total on the two tandem "drive" axles on the truck. There are two tires at the end of each axle, so four per axle, eight total at the drive axles, and ten total on the truck.
34,000 pounds on the two tandem axles on the trailer, two tires at the end of each axle, eight total on the trailer axles, 18 total on the truck plus trailer rig.
34K + 34K + 12K = 80,000 pounds = 40t, if the trailer is fully loaded to max. It's about 35,000 pounds total if the trailer is empty.
So you should include in your calculations that the load is spread out over eighteen tires, as above.
There is also bridge loading to consider. https://en.wikipedia.org/wiki/Federal_Bridge_Gross_Weight_Fo...
Building an entire truck isn't free from cost and environmental impact, nor is maintaining it.
Fuel usage also increases with more trucks.
There's also an overhead each truck has that scales differently from how much it lugs, based on fuel it needs to carry and space for its driver.
On the other hand, wouldn’t reducing the amount of cargo a single truck can carry makey individual truck driver less valuable?
The end result would probably depend on a lot of other factors, including the supply and demand curves for alternative forms of transportation (trains, boats, investment in autonomous solutions), as well as the supply and demand curves of the goods being transported (because if the cost goes up to pay for more truck drivers, maybe people will just stop buying that product).
My truck gets at least 6mpg, usually 7.5, sometimes 9, and I've seen 10 once.
However, an even more material-efficient solution would be to use railways instead.
You're absolutely quibbling though.
> So you should include in your calculations that the load is spread out over eighteen tires, as above.
The fourth power rule is specifically about axle load, not about wheel load. It's also an estimate / rule of thumb (which is why it's so useful), not a precision instrument.
But hey if you want more precision than the FPR we can do more precision: https://pavementinteractive.org/reference-desk/design/design...
As the link notes, road engineers usually work in LEF/ESAL (ratio to a standardised 18000lbs axle load), and provides some conversion tables.
Assuming a relatively large 4000lbs sedan this is 2000 lbs per axle, or 2x0.0003 LEF = 0.0006 LEF.
A fully loaded truck would be ~0.3 for the 12000lbs front axle, and 1.11 for each of the rear tandem axles, for a total of 2.52 LEF.
2.52 / 0.0006 = 4200. Which shows that the fourth power rule's 4096 was pretty close but if anything underselling it.
Misunderstood that, sorry.
But, there is also something called a "super single" that's a double wide single wheel/tire, with one on the end of an axle rather than two. I'm told they're cheaper and lighter total, as opposed to the more common two per end. I've pulled a few trailers that had them. I don't really know why one or the other, I just drive them.
Let's not forget the context of this discussion, however. Fourth power expressions are still fourth power expressions after multiplication by a constant factor. 4/18 is a constant factor.
I don't know if doubling tire counts really does this, but it's hard to see why twice as many axles would help but tires per axle would not. It's possible (the pressure underneath the tires is reduced, but the tires exerting pressure on the road are closer together) but counter intuitive to say the least.
And there's no proof in this thread that it doesn't help except for masklinn's misinterpretation of the original study.
$10 for a bike doing 1000 miles a year, so 1 cent a mile. Gross axel weight about 100lb.
So axel weight of 1000lb would be $100 a mile.
F150 at 2500lb would be $4,000 a mile.
I suggest putting the first year on the sale price, so that $200 bike costs $210, and the $60k f150 costs $60 million.
Such a tax would eliminate marginal uses of trucks but not eliminate trucks entirely (since it would be a higher but not ridiculous tax).
It also works as a reductio against any wear-based tax on bikes, since it would imply an absurd tax on trucks.
[1] https://news.ycombinator.com/item?id=22519021
(Edited over past hour to fix numerous typos.)
Anyone who has done any amount of virtual traffic engineering (aka: Factorio, City Skylines, OpenTTD) knows that intersections are where the bottlenecks are.
Its incredibly difficult to design a max-throughput intersection. Roads have a huge amount of throughput, most "traffic" just gets stuck at offramps and traffic lights.
Narrowing a road to make room for bike lanes is a lower cost than people might think. If you're all going to get stuck at the next intersection anyway, it doesn't matter if you're a 2-lane, 4-lane, or 8-lane road.
While that certainly has the desired effect of reducing car traffic to the area, it also increases the difficulty and expense of travel to the area. We’re seeing this in Oakland now, where they’re putting in bike lanes and taking away parking, while simultaneously doing nothing about the limited public transportation system.
If you want to reduce vehicle traffic without seriously impacting the shops and restaurants in the area, you have to use both knobs available to increase people’s use of public transportation: make it harder and more expensive to drive a car, while also making it easier (and, preferably, cheaper as well) to take transit. One without the other is a disaster.
Oakland is littered with cars along roads in every neighborhood you go on, and the police barely enforce anything resembling traffic code (due partially to complicated historical reasons). In some neighborhoods, I've seen duplexes with more land area in cars than living space (so is it a wonder that poorer people here live in their cars when it's so easy to own and park a car?)
A bike lane or two makes it cheaper for most folks (yes including the folks living in the pop-up Oakland housing shelters, they own a lot of bikes) to safely move around, and reduces traffic from our generally saturated roads. Given the limited paving budget here (and how tectonically active the hills are), it's a wonder that bike infra has taken so long.
Moreover, the heavy private vehicular traffic in the area makes it very difficult for buses to navigate their routes in a timely manner, and taking parking off the road for bike lanes and BRT is a much cheaper way of enabling transit in the area that laying down rail.
(B) Use a trailer the kids can ride in
(C) Don’t use a bike for a 15mi commute. Better still, don’t do things 15mi away. That’s so damn far what the hell
If you halve the capacity of the road, you're just going to spread the same cars (and congestion) among twice as many lights...and make traffic far worse.
Isn’t this proportional to the number of lanes in the road?
Oddly enough, sidewalks are the most efficient use of space, but require good public transportation and extreme density to reach that threshold.
Besides, I think the economy would be much healthier if everyone was riding their bike recreationally (healthy bodies, healthy minds). And a much bigger boost to the economy than a delivery truck driving 10 miles to deliver a $2 package.
Lower costs for the customers and higher reliability when you ship by truck means rail is not really a consideration even though it would be better for everyone if it actually worked.
He had many war stories to tell related to the trucking industry. In one, they had developed a scale that could measure the weight per axle of vehicles on the roadway without requiring the vehicles to slow down. They wanted to embed these in a few places to prove how bad things really were with overloaded trucks.
The trucking industry bought off some congress critters who would only allow them to put the scale at one clearly marked location on an interstate, in one lane. The lane next to the scale lane was crushed by all the trucks driving in that lane to avoid the scale.
Trucks should really only be a last resort for the last mile to the store and the rest should be sent by rail or boat and loaded onto trucks if necessary.
They also have huge externalities when it comes to damage to other cars, when my car is hit by rocks on the road it is always coming from a truck.
I was annoyed at these failures and some light reading. You can make more robust roads by making them thicker with a sturdy foundation. Of course this comes at a much higher cost. For example, the autobahn pavement thickness is 27 inches. Whereas by me they mill a few inches off the top of whatever sad situation in below and top it with another 4 inches or so. This is because robust roads are costly and there are so many other things in a muni budget which need attention. So they compromise and lay down a cheap road.
But at least the weight of a lorry consists of mostly the goods being transported. The more pertinent comparison is a bicycle vs single-occupant "SUV". Unlike lorries, those things are tearing up smaller roads in town centres making the roads barely usable by smaller cars, let alone bicycles, despite the fact that cyclists contribute equally to road maintenance.
Those SUVs also require larger brakes which is a major non-exhaust emission. It's high time to start taxing these vehicles heavily and I think using the fourth power of axle load seems like a sensible way to do it.
The tyre pressure exactly matches the pressure on one spot on the road surface, so if pressure is higher, a smaller area of the road receives more downward force, causing it to bend and flex, and eventually break up.
Apparently not in any way relevance in face of the fourth power rule, as road authorities worldwide just use the 4th power rule for road wear estimates, without accounting for minor factors (type of axles, axle arrangement, surface contact and suspension systems).
Could you explain why? (I can't view the Google books link.)
Given the amount of consumption (of physical goods) that's a significant amount of tire wear.
Unless you walked naked out into the woods and built your life entirely from found materials, literally everything in your life was at some point or another hauled by a truck.
Everything.
This is not a hyperbolic way to make an argument, it's the truth. Sometimes you'll have to go pretty far back the chain of events, maybe as far as raw materials, but at some point (probably several) X was on a truck for any X.
A hippie commune that grow all their own food living off the grid? Their clothes, their tools, the paint on their house, it all rode on trucks.
Two-ish years ago truckers in Brazil went on a strike to protest increased gas prices and corruption and it only took three days before the president ordered the military to force the trucks into moving again. That's how hard it hits if trucks stop moving.
The military couldn't do shit though because the trucks hauling the diesel powering the military vehicles were part of the protest so they got nowhere.
If all the trucks stop right this second, we'll be living in post-apocalyptic chaos by Friday. No joke.
Yes. Electric vehicles with their heavy batteries also make things worse.
Have you been to a Texas city? They're full of F-150s driving around a single person and an empty bed on paved roads.
Sure, farmers and contractors use trucks as trucks, but thousands of people use them as commuter cars. Most pickup trucks are used as trucks once in a blue moon.
If you want to make this argument you should account for the weight of a loaded F150
Shldr Hip Head Leg
Model S: 57.7 55.0 38.8 42.7
Camry: 57.7 55.4 37.5 42.1
Model 3: 56.3 53.4 40.3 42.7
Corolla: 54.0 53.9 38.0 42.0
WB Len Wdth Hght
Model S: 116.5 196.0 77.3 56.5
Camry: 111.2 192.7 72.4 56.9
Model 3: 113.2 184.8 72.8 56.8
Corolla: 106.3 182.5 70.1 56.5Model S P90D is 120 cu ft (41lbs per interior cubic foot).
Road wear scales with the fourth power of axle load, so heavier vehicles do much more damage than one might expect.
Take a 40t truck with 5 axles vs. a small car with a weight of 1t and two axles (e.g. VW Polo, maybe an older VW Golf might only weigh 1t as well):
(8t axle load / 0.5t axle load) = 16^4, i.e. the truck puts 2^16 (65536) times as much wear on the street as the car.
(8t axle load / 1t axle load (SUV)) = 8^4 = 2^12, even comparing it with an SUV and an axle load of 1t each, the truck is still 4096 times worse.
https://en.wikipedia.org/wiki/Road#Maintenance
https://books.google.de/books?id=7Yqxyefv-VAC&pg=PA252&dq=4t...