Bridge Laws in Texas

Discovered yesterday that Texas actually enforces bridge laws, although being a rookie aggregate hauler he granted me mercy and didn't ticket me for being 4500lbs overweight on gross.
I'm only about 3 weeks into this job, and my trainer just said "Your overweight permit allows you to carry up to 84000, but they can still get you for being over 37400 on tandems."
What he forgot to mention? Permit is only valid on state highways and Farm to Market roads, not the Interstate lol.
So DOT flags me down as soon as I merge onto I35, and I have the joy of a full inspection.
I've never paid attention to bridge laws, as I thought they only really mattered once you started adding axles. Trooper breaks out the tape measures,turns out my full bridge is only 49.6 feet, but to simplify things he rounds it up to 50. My overweight permit is for 5% variance over gross, so I'm assuming 84k on 80k. But considering my bridge is only 50feet, I can only run 79000 standard, and a tad under 83k with the permit.
Because I was on the Interstate(for 3 miles btw) running 83500, I was 4500lbs overweight on gross.
A few written warnings(couldn't find my trailer registration or inspection sheet) then let me go with a promise he will be issuing tickets if this ever occurs again.
I really think this is something they should have mentioned during orientation, or at least my trainer should have mentioned. I've been loading around 83500 and running the interstates for 2 weeks now.

 

I understand that now, but it would have been nice for the company to inform of that. Running out of the Hanson quarries they automatically load up to 83500 out of the automated silos

 

I was told by my company I could run 84k, and my trainer had me on the interstates all the time.
And coming from standard 48/53ft trailers and sleeper cabs, bridge laws never came into play.

 

Meh.... I'll admit fault for not reading permit details. But company had a responsibility also.