Ok here is an NTEP ( National Type Eval Program ) test of a prototype heavy duty off road scale , average truck crossing this scale is around 350,000 lbs , 9-11,000 weighments per month ( or so I am told ) , this was a few years ago , there HAVE been some modifications since then .
This is a view of the scale from the side being loaded with test weights ,

we had to consentrate the load in various places on the scale , ( each one of those silver blocks weigh 1,000 lbs ) ,

Here is some prospective for you , these guys are about 6' tall ,

Trucks for Foots ,

Loading up the final test , unknown weight ( steel coils at about 50-60k a piece ) and known weight ,A+B should equal C (and yes the carts are certified as well ),

And this ladies and gents is the final load ,

425,060 lbs , the inspecter had us leave it on the scale for over 2 hours , then clear it all off , then do it ALL again on both ends of the scale .
The scale zeroed off and repeated the weight on BOTH ends Both time he had us do it !!!!!!!