Ancillary Justice (Ann Leckie)

Facts about ancillary justice:

* The main character is a warship AI (sometimes in the warship and sometimes in remote humanoid drone)
* The language spoken or narrated by the main characters has a gender neutral pronoun, rendered in English as "she". This isn't perfect, but works pretty well. When speaking a foreign language, pronouns are translated as "he" or "she".
* There's some quite rich worldbuilding. The empire the main characters come from feels matter-of-fact, mostly full of normal people, despite being elitist and entitled as a culture. But without being ostentatiously perfect or ostentatiously evil.
* More interesting questions are raised than it has time to answer.

It left me feeling it could have done a bit more, but it was a very interesting modern example of slightly-Banksian space opera.

Flash hazard lights to say "thank you"

For a while, I've noticed cars flashing both indicators simultaneously (presumably by turning hazard lights on then off again) to say "thank you" for letting them in.

I think I first noticed it by lorries -- google suggests it may have been a lorry driver custom first.

I really like the idea of being able to say "thank you" or "sorry" as well as "please" or "get out of my way" when driving.

Am I right that it's new, or did I just not notice when I started driving?

Presumably it's not allowed (just like flashing headlights to say "excuse me" or "after you" or "do you know your lights are on/there's something wrong with your car/etc" was never an authorised use according to the highway code). Is it a bad idea, or not?