This is a good point...rather than turn off the lights, set them to flashing amber as suggested. Normal rules of the road then apply! Treat as a roundabout and give way to the right. Makes a great deal of sense really.
It was even easier than that, in Munich at least.
During the night, they turned off the lights on the "main" route completely and only had the flashing lights from the side roads. This means that anyone on the main route didn't have to even slow down across the junctions and anyone on the side roads would know, from the flashing ambers, that they'd have to give way. It also had the benefit of not having peeps burning fuel on a red light when there was no-one to wait for.The only downside, IMO, was that the lights would click as well, which was a pain if there was a set within 100m from your bedroom window.
In Sweden, they had lights which were 4-way red, and a car approaching from any direction would change them to green for a few seconds.
Having experienced both of those smart (IMO) solutions in the mid-90s, it's frustrating as heck that we are still in a backwater in this country. We shouldn't even need to be discussing the rights and wrongs of an RLJ at 3am, we should be asking why the freaking lights are still burning electricity and wasting petrol at that time.