Flashing tail lights in the Group Ride: Why they are more annoying than useful

It's the end of the day. A long, exhausting day is behind me and tonight's Group Ride is exactly what I've been looking forward to all day. Fresh air, good company, switching off.

The group rolls off, it gets dark and then it starts. It flashes red in front of me. Next to me too. All in a different rhythm, all in my field of vision. Almost immediately, I can feel each flash directly in my head. I know I'm prone to headaches. If I have flashing tail lights in front of me, it starts immediately.

To flash or not to flash

In city traffic, travelling alone between cars, an additional flashing light to the red light with continuous lights may be useful. It is noticeable. I don't deny that at all.

But in the Group Ride, the situation is different. I'm not 50 metres behind you. I'm 2 metres behind you. I can see you. What I don't need is a permanent warning signal in my field of vision that gives my brain a shock every second.

I often wait a few minutes, then I can't stand it any longer and ask my fellow travellers to switch to continuous light. Each time it takes strength and effort. Most of the time I am met with understanding, sometimes the button that switches from flashing to steady light is simply pressed without comment.

What the StVZO says

The Road Traffic Licensing Regulations stipulate that rear lights on bicycles must be permanently illuminated. A pure flashing light without a simultaneously active continuous light is not permitted. There is only an exception if the light has a corresponding licence and the flashing light runs in addition to the continuous light - not instead of it.

In other words, a flashing rear light does not fulfil the legal requirements in most cases.

"But you can see flashing lights better!"

That's right - the eye reacts more strongly to changes than to continuous light. But flashing lights have a catch: distances are harder to judge when a light disappears rhythmically. And in a group ride with several flashing lights at different intervals, there is no more information gain - just noise for the brain.

If you really want to be seen better, rear lights with a brake light function are the better option. Permanent light in normal operation, automatically brighter or flashing briefly when braking. This is sensible information - not permanent flashing without a message.

What I wish for

I can't tell you whether you should ride with a StVZO-compliant rear light or not. But my advice is: switch it to continuous light before the group sets off. Charge the battery beforehand - continuous light consumes more energy than flashing lights, so take that into account.

Group Ride means taking each other into consideration. When choosing lines, at speed, with hand signals. And the lights too.

And if you're travelling solo: