Reminds me of how the damage to roads scales with the weight of the vehicle to the 4th power, so someone driving a 6000lb pickup does 16x more damage to roads than a 3000lb sedan
It’s more about a minimum of weight or pressure that affects it. So the higher the pressure the more likely it is to flex the road where a small vehicle with light pressure might not make it flex at all. The heavier it is the more the weight will flex the subsurface and cause more damage.
“To give you an example of that impact, let’s do a quick calculation. Here in New Zealand, the heaviest vehicle allowed on (some of) our roads is the 50MAX truck. It has nine axles and a total weight of 50 tonnes, so the load-per-axle is 5.55 tonnes. The best-selling car in NZ in 2022 was the Mitsubishi Outlander. It weighs 1.76 tonnes, so its load-per axle is 0.88 tonnes. The fourth-power law says that to calculate the relative stress that these two vehicles apply to a road, you take the ratio of their loads-per-axle and raise the result to the fourth power. In this case, (5.55 / 0.88)4 = 1582. In practical terms, it means that a 50MAX truck applies as much stress to a road as 1,582 cars (or quite literally billions of bicycles)”
Reminds me of how the damage to roads scales with the weight of the vehicle to the 4th power, so someone driving a 6000lb pickup does 16x more damage to roads than a 3000lb sedan
How does double the mass increase the damage 16 fold? I understand surface area vs volume, but that doesn’t seem relevant when working with mass
It’s more about a minimum of weight or pressure that affects it. So the higher the pressure the more likely it is to flex the road where a small vehicle with light pressure might not make it flex at all. The heavier it is the more the weight will flex the subsurface and cause more damage.
https://www.forbes.com/sites/lauriewinkless/2023/08/30/how-roads-fail-and-why-theyre-set-to-get-worse/
“To give you an example of that impact, let’s do a quick calculation. Here in New Zealand, the heaviest vehicle allowed on (some of) our roads is the 50MAX truck. It has nine axles and a total weight of 50 tonnes, so the load-per-axle is 5.55 tonnes. The best-selling car in NZ in 2022 was the Mitsubishi Outlander. It weighs 1.76 tonnes, so its load-per axle is 0.88 tonnes. The fourth-power law says that to calculate the relative stress that these two vehicles apply to a road, you take the ratio of their loads-per-axle and raise the result to the fourth power. In this case, (5.55 / 0.88)4 = 1582. In practical terms, it means that a 50MAX truck applies as much stress to a road as 1,582 cars (or quite literally billions of bicycles)”