What is the rationale for the Bridge Laws?

Both trailers are 53’ with 18” pin settings. And the trailers have nothing to do with determining the overall gross weight in my example. Proving that you’re confusing a KPRA reg with the bridge formula.

 

Its that front aux axle spread away from your drives, at a guess gives more weight, but this isnt my schtick, i play with my baby 5 axle setup

 

Look at the pic close, and you’ll notice a slight difference on the truck. The trailers, although one has different spacing, don’t play a part in the difference in gross weight. But when you see the one difference you’ll see the effect of the bridge formula.

 

That's the same truck. It's just dirty in one pic.

 

Unit #s
97a vs 104a, nope

 

You got it! That one little change allowed the truck on the bottom to be 105k gross weight, where the top truck could only be 104,500 gross. The bottom truck had a larger 7 axle bridge, the measurement between axles 2 and 8.

 

Correct, but weight carried depends on axle grouping, gpd pointed out your trailers with tandems (4'2" between centers) vs a spread axle (most often 10'2" between axles) gives different weight capabilities, 34k vs 40k, this is just the same, just on a tractor

(and apparently i was wrong )