A high-vis jacket makes a very effective Cloak of Invisibility (I am told) if you want to explore somewhere outside that you're not supposed to be.

(Raak) Mm, I hadn't thought of that. Could be useful for committing gross trespass in railway tunnels. (I have actually done that). It's a bit like donning police uniform without the risk of committing the serious offence of impersonating a police officer. One could get a hard hat as well and be pretty well untouchable. The more I think about it the better it gets. You could give one as a Christmas present to someone with low self-esteem but obviously they would find it difficult to adopt the swagger. Let us raise a glass to The Law of Unintended Consequences.

It is now compulsory to carry hi-viz jackets in cars when driving in France. Not just for the driver either, one for each seat and they cannot be stored in the boot.

[Rosie] Are you sure they weren't just wearing your away kit of a couple of seasons ago? ;)

(Softers) That sounds most un-French unless I've misjudged the place. Where are you supposed to store them? When is it compulsory to wear them, and if it isn't, what are they for?
(Tuj) Yes, not good, was it.