Michael V said:

dv said:

The Rev Dodgson said:

From TATE:

“A 1988 report by the Australian Road Research Board stated that the rule is a good approximation for rutting damage, but an exponent of 2 (rather than 4) is more appropriate to estimate fatigue cracking.

A 2017 report commissioned by the New Zealand Transport Agency found a wide variation in the best-fitting exponents for a power law on 4T axle loads vs 6T axle loads, depending on the current condition and type of the roading. As a very rough summary of its highly detailed findings: A 9th-power law is most predictive when the road is barely able to withstand the 6T load; and the per-crossing damage is roughly linear to axle-weight when the pavement is able to withstand much higher loads than 6T per axle.”

so:
1) It’s not that simple.
2) It’s the top end axle loads (i.e. heavy trucks) that do the damage, and the difference between mid-range and bottom of the range is not that much.

3/ a 2nd power law still means it is a x4 difference.
4/ there are hundreds of thousands of heavy trucks in Australia. There are fkn millions of 2 to 3 tonne utes being utilised as family cars.
5/ At this stage the use of heavy trucks to move goods is a necessity. The selection of a 2.5 tonne ute to be used as a family car is almost always a needless extravagance.

5+/ And because it is a “Work Ute” it, its fuel and its maintenance is subsidised through the tax system.

All around here, they all have land cruisers for the wife to drive to the shops and Toyota land cruiser utes for the lads. All subsidised because they own a farm or three.