What is the rationale for the Bridge Laws?

Discussion in 'Experienced Truckers' Advice' started by expedite_it, Oct 15, 2022.

  1. Long FLD

    Long FLD Road Train Member

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    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.
     
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  2. expedite_it

    expedite_it Road Train Member

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    What does KPRA stand for?

    I've gleaned from other responses on this thread the KPRA refers to what i've always heard everyone else refer to as bridge laws.

    That all makes sense to me.

    I guess in California they are real concerned about people not hitting signs with the middle of their trailers then.

    When you hear other people talk about KPRA in meatspace, do they typically refer to KPRA as the bridge laws?
     
  3. skallagrime

    skallagrime Road Train Member

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    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
     
  4. Long FLD

    Long FLD Road Train Member

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    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.
     
  5. rch10007

    rch10007 Medium Load Member

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

    expedite_it Road Train Member

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    The only difference I see in the pictures of the two trucks that Long FLD posted in post #9 is that the bottom tractor-trailer has a bigger space between the second axle and the third axle than the tractor-trailer in the picture on top. But I don't see how that would affect the gross amount of freight that each tractor-trailer would be allowed to haul.
     
  7. skallagrime

    skallagrime Road Train Member

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    Unit #s
    97a vs 104a, nope
     
  8. Long FLD

    Long FLD Road Train Member

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    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.
     
  9. skallagrime

    skallagrime Road Train Member

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    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 :p)
     
  10. expedite_it

    expedite_it Road Train Member

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    That's interesting, although a 500 pound difference is a negligible difference when you're talking about over 100,000 pounds of freight.