Generally what Wayne said is true
I would add , as I have checked with CHP , and have a flatbed
Stopping at scales is not required if you have the TC on
I was told I probably should roll thru the empty lane if it wasent , but if I blew past the scales it would be up to the weigh master if I would be chased down , I see flatbeds not stopping all the time , but don't frequent area`s with scales since I put on the flatbed
The main issue is if you put any work related material in the bed of a non stock truck box , or in the stock box and you weigh over the CAL limit , I want to say its a little over 11k , its 10001 lbs federally , or tow anything work related you need CA #s , and DOT #`s posted on your truck
Like most things in CA its not totally enforced , and discretionary officer to officer , until you least expect it
There are thousands of flat beds rolling the rural areas of Ca with no problem , but if they want to pull you over they may not need to look for a brake light that's gone out