We've probably thrashed this subject beyond any useful point, but I have one more data point to add.  Today I went out with my local (French) bike club on a regular Wednesday morning ride.  There were about 40 riders and about 35 of them had lights on their bikes.  Of those 35, about 30 of them were...blinking.

This is the south of France, where things are a little "looser" with regard to rules and regulations.  But down here, for daylight riding, the on-the-ground consensus is that blinking is OK.   

One of our members is a policeman, by the way.  He was on the ride.  :)

totally agree. Why do some cyclists insist on blinking headlights on a bike trail for example? Nuts, and they’re blinding. Thank you France and Germany. I don’t use lights in Europe, people know how to drive there ( ok, making gross generalizations…in France the Renault Cleo drivers suck, in Germany and Italy, BMw, Spain - best country, no one speeds, they give you 1.5 meters space, etc. ). 

Here in Vancouver, it's usually because they turn the light on when they start riding and don't turn it off when they come to a trail.  Some people even leave their lights on at a coffee stop.  Some riding clubs mandate the use of lights at all times (a friend belongs to one such club).

I *do* use lights in Europe, a taillight always for visibility and a headlight when needed (tunnels, poor visibility in fog or rain or at dusk).

Just a heads up.  

Garmin has just announced an update that will remove the blinking from the Varia RTL515 and RCT715.   It's numbered version 5.50 for the RCT715 and 3.36 for the RTL515.

So if you live in France and want to continue to blink, you probably don't want to install these updates!  I have no idea what would happen if you installed them in other countries.

Here's a link to a French-language article describing the update: 

https://www.matosvelo.fr/index.php?post/5049/les-radars-garmin-varia-sont-mis-a-jour-pour-se-conformer-a-la-legislation-francaise.

HTH

I just scanned the article and found it interesting.  I had forgotten Varia taillights blinked (with increasing speed, I seem to remember) as vehicles approached.

I also saw that blinking lights are forbidden at night or when daytime conditions are not optimal (foggy, perhaps?) and seemingly not during normal daytime riding.  I’d love to know the reasoning behind these regulations.