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My understanding is that road damage is linked to tire pressure and contact surface, and that bus and trucks with bigger tires have a larger contact surface hen

My understanding is that road damage is linked to tire pressure and contact surface, and that bus and trucks with bigger tires have a larger contact surface hence the same pressure as a car and therefore don't do more damage than a car.

mamon 8y ago
Regarding pressure/road damage: Polish roads in particular are marked with grooves created by heavy trucks. And we know for sure that it's because of trucks because it only happens on the rightmost lane, where they typically drive. Yes, trucks have more wheels and therefore bigger contact surface, but it only partialy compensates bigger mass. Pressure on road is still few times bigger than of typical car. Buses however, are big but not that heavy, so they are not as bad as trucks.
WhompingWindows 8y ago
See the following analysis by Brad Templeton, a SDC expert: Road wear There is strong potential to reduce the damage to roads (and thus the cost of maintaining them, which is immense and seriously in arrears) thanks to the robotruck. That's because heavy trucks and big buses cause almost all the road wear today. A surprising rule of thumb is that road damage goes up with the 4th power of the weight per axle. As such an 80,000lb truck with 34,000lb on two sets of 2 axles and 6,000lb on the front axle does around 2,000 times the road damage of a typical car! An interesting solution is now possible. With fully self-driving trucks (or platoons with nobody in the rear vehicle) you can have two half-weight trucks, which would do 1/8th the damage. 4 1/4 weight trucks would do roughly 1/16th the damage. This is a bit more expensive in fuel and truck wear, though you can get back some of it with platooning. The platoon can space out further on bridges to avoid stressing them. https://ideas.4brad.com/otto-and-self-driving-trucks-what-do-they-mean https://ideas.4brad.com/otto-and-self-driving-trucks-what-do...
Mediterraneo10 8y ago
> bus and trucks with bigger tires have a larger contact surface hence the same pressure as a car and therefore don't do more damage than a car. In parts of Europe where the temperature soars over 40°C in the summer, trucks are forbidden from driving during the daytime because when the asphalt softens, they do more damage than a car.

mamon 8y ago

Regarding pressure/road damage: Polish roads in particular are marked with grooves created by heavy trucks. And we know for sure that it's because of trucks because it only happens on the rightmost lane, where they typically drive. Yes, trucks have more wheels and therefore bigger contact surface, but it only partialy compensates bigger mass. Pressure on road is still few times bigger than of typical car. Buses however, are big but not that heavy, so they are not as bad as trucks.

WhompingWindows 8y ago

See the following analysis by Brad Templeton, a SDC expert: Road wear There is strong potential to reduce the damage to roads (and thus the cost of maintaining them, which is immense and seriously in arrears) thanks to the robotruck. That's because heavy trucks and big buses cause almost all the road wear today. A surprising rule of thumb is that road damage goes up with the 4th power of the weight per axle. As such an 80,000lb truck with 34,000lb on two sets of 2 axles and 6,000lb on the front axle does around 2,000 times the road damage of a typical car! An interesting solution is now possible. With fully self-driving trucks (or platoons with nobody in the rear vehicle) you can have two half-weight trucks, which would do 1/8th the damage. 4 1/4 weight trucks would do roughly 1/16th the damage. This is a bit more expensive in fuel and truck wear, though you can get back some of it with platooning. The platoon can space out further on bridges to avoid stressing them. https://ideas.4brad.com/otto-and-self-driving-trucks-what-do-they-mean https://ideas.4brad.com/otto-and-self-driving-trucks-what-do...

Mediterraneo10 8y ago

> bus and trucks with bigger tires have a larger contact surface hence the same pressure as a car and therefore don't do more damage than a car. In parts of Europe where the temperature soars over 40°C in the summer, trucks are forbidden from driving during the daytime because when the asphalt softens, they do more damage than a car.