I was getting gas and saw that there was no line for the scale. I had my new 24' trailer behind the motorhome, and so I got a reading. Then, at home, I used a load-cell type scale to weigh the hitch, then adjusted the results.
If you're into math, there are ways to get your tongue weight pretty accurately from a bathroom scale that's one half of a support for a beam that holds the weight of the hitch on top of it. The other half of the beam would be on a block the same height. The distances between the points are adjusted in anticipation of not overloading the bathroom scale. Then, do the math to find the % of force on the scale to get the true reading.
Very informative to find out what moving a few things around does to the hitch weight.
The weigh stations I've seen in the South don't want you to even slow down and ask them what the weight is, since there's usually lots of trucks in the line, too. Opinion has been split on whether a cargo looking trailer has to stop or not at those, but once they see the motorhome, they just wave me past, meaning I didn't break some huge weight threshold that a huge truck might.