You can’t really stop road ragers from getting out of their car with the intent to hit someone. You can indeed convince them that attacking armed strangers is a bad idea—without anyone being hurt.
Providing context means, well, providing context, not just tossing out a composite figure without background or breakdown. A good actual context for that would be the not-gun-related road rage assault figures before and after, and what percentage of that increase is brandished (no one injured) vs shot/shot at (violence that should be prevented/reduced).
Also, I wouldn't exactly feel good if someone cut me off for driving a little too slow for them and they waved a gun at me. Somehow these arguments make that OK as if it isn't an escalation or is "oh well gee at least we didn't fist fight."
To provide context, here is some data on that:
"cases of road rage involving a firearm — where someone brandished a gun or fired one at a driver or passenger — more than doubled to 620 in 2016, from 247 in 2014."
https://www.nytimes.com/2017/04/25/us/road-rage-guns.html
That doesn't amount to "civilization-breakdown", but whether it's a level that's worth worrying about is something different people will feel differently about. I suspect it is a higher number of cases (per capita) than many other countries with stricter gun laws.