Why should that be required? Let people do as they will and impose penalties for problematic behavior (including negligence). I lived in a state with safety inspections and AFAICT it was little more than yet another disproportionate speed bump for the poor and a complete waste of time for society at large.
I do see the merit of inspecting larger trailers (such as for boats) once a year given the combined increased likelihood of incompetence and risk to life when things go wrong. But even then I think it doesn't actually accomplish much in practice. The time and effort would be better spent on targeted public education campaigns, possibly mandatory.
For emissions, again who cares. Regulations imposed on the high volume manufacturers broadly solves all the issues that are easy to solve. The rest are either willful violations or collectors. The latter is technological in nature and inevitably gets grandfathered for both safety and emissions everywhere I've lived.
I do see the merit of inspecting larger trailers (such as for boats) once a year given the combined increased likelihood of incompetence and risk to life when things go wrong. But even then I think it doesn't actually accomplish much in practice. The time and effort would be better spent on targeted public education campaigns, possibly mandatory.
For emissions, again who cares. Regulations imposed on the high volume manufacturers broadly solves all the issues that are easy to solve. The rest are either willful violations or collectors. The latter is technological in nature and inevitably gets grandfathered for both safety and emissions everywhere I've lived.