MonsterX
Emperor Mongoose
There's no universal authority on Earth IRL, yet there there are standards for safety on ships - SOLAS convention- and in many other areas too. I don't assume a universal authority, and authorities in different areas will do things differently, but mostly they'll try to keep business running smoothly, and there will be various standards and agreements which make sure it does. Passengers taking completely unnecessary risks on low berths is business not running smoothly. There's going to be places where that regulation doesn't happen. These are often the kind of places where PCs end up, for whatever reason, but that's just because PCs are gonna be PCs, and the sleazy and corruption of those kinds of places can be contrasted with better run localities to provide pathos.You seem to assume that there is a "universal authority" who writes and enforces regulations. I am aware of none that exist in Traveller. Is there a reference to this somewhere? This would seem to tie back into the whole "Dark Imperium" thing.
To take the military unit example, the Imperial Marines will have an SOP that makes sure accidents don't happen to frozen watch and this will be standardized across the Imperium because they are the Imperial Marines. It costs a lot to train a marine, and it undermines unit cohesion if they obviously don't care about their people. A well run mercenary unit will have its own SOP with the same goal and for the same reason. A badly run mercenary unit might not, or they might have but then fxck it up. The PC that gets mixed up with this last kind of unit realizes he's in a bad place, when you show him the low berth procedures - and the ontrast with his time in the Marines.
In commercial shipping, passengers will be aware of the danger of low berths and want to know it is safe. Governments - planetary or otherwise . may have safety inspections in some places - but IMTU, the Imperium as a whole is not that systematic. So companies will have their reputations, and companies that don't have reputations will get certified by private organizations who inspect and certify. They'll slap safety stickers on their machinery, and give certificates to the captain to show passengers and authorities that it is a tight ship. Obviously, there will be corrupt inspectors, yahoos who aren't certified, forged certificates etc. But for most people, for most of the time, they'll be travelling in a safe casket. This is just for the Imperium though: other places will have tighter regs, or sometimes looser ones.
The overall coherence and integrity of these systems will be higher or lower in different times and places. It's not whether the Imperium is Dark or not - having a Light part of the Imperium helps make the Dark seem really dark.