Yeah but the article claims they just have a flap without any support, so no improved safety. Having actual sideguards adds weight independent of the aerodynamic issue.
Maybe 1,000 lbs of weight, so instead of 40,000 lbs cargo trailer would be limited to 39,000 lbs, but lots of people would not get decapitated. There is also no reason why states could not allow extra 1,000 lbs of total vehicle weight when trailer is equipped with side-guards.
Absolutely! I pointed this out only to address the arguments from the industry side, as far as I understand them. I’ve seen many debates getting hijacked by “smart” contrarians who are accusing people of misrepresenting the issue.