What are the most common out of service violations?

Here is a pdf with the most violations. I know it's not OOS like you asked, but you can look at the list and pull the OOS ones out.
Page 23 is driver violations, and 24 is vehicle violations.
https://www.fmcsa.dot.gov/sites/fmc...de to Large Truck and Bus Statistics 2021.pdf

 

Roadside Inspections Visualization Tool

Select the Violations button and hold your cursor of a bar on the graph to see a pop-up with the text description of each violation category.

 

Off the top of my head, I am going to say it is either Brakes, Loose or frayed wires, or wiring harnesses.

 

most common would probably be anything brake related

 

I think it has to be a break, which is from point A to point B, or a crack within the drivers 5x8 view. They give a month or 2 leeway on ifta stickers

 

anything in the drivers view is out of service as far as i understand.

 

IFTA Stickers have 60 day grace period. As far as your window, as long as it doesnt affect your line of sight or something like that. I had something fall off a flatbed smash in my passenger side part of the windshield(single piece windshield) there was a hole in the window and cracked very bad. The Indiana state trooper actually said I was ok to drive it as long as it didnt affect my view.....