When driving at night, you’ll occasionally see bicyclists with flashing lights attached to their bicycles. Why? Here’s a quick rundown on why cyclists use flashing lights, what you should expect from a cyclist whose lights are flashing, and whether or not you should put flashing lights on your bicycle.

Why Do Cyclists Use Flashing Lights? Cyclists use flashing lights to make themselves more visible to drivers. Cautious bicycle riders understand that the most important thing when riding in the dark is to make sure that drivers can see and avoid them. Flashing lights attract more attention than steady lights, making them a popular choice for safety-conscious cyclists.

Flashing Lights vs Steady Lights

While people will certainly notice a flashing light more readily than they’ll notice a steady one, flashing lights aren’t a one-size-fits-all solution. Cycling safety experts are keen to point out that it’s more difficult to judge the speed or distance of a flashing light than it is to judge the speed or distance of a steady light.

This means that in some cases, a flashing light can be MORE dangerous than a steady light for a cyclist. Sure, you’ll attract the attention of the drivers around you, but it’s equally important that they know exactly where you are. An overzealous driver might bump into a cyclist if he can’t accurately estimate the distance or speed of the rider.

What Does It Mean When A Cyclist’s Light Is Flashing?

There’s no hidden cyclist morse code used by bicycle riders with flashing lights. Instead, they simply want to make sure that you (or anyone else) notices them. If you see a cyclist with a flashing light, treat them as you would any other cyclist and give them some healthy breathing room as you drive, walk, or cycle past them.

If a cyclist has detached their light from their bicycle and is waving it around or has crashed, again, treat them like you would any other cyclist doing the same thing. If you’re comfortable, consider approaching and seeing if there’s a problem. If the situation looks dire, alert the proper authorities. The flashing light is simply a means to attract your attention — the rest of the situation should dictate how you act.

Should I Put A Flashing Light On My Bicycle?

Flashing lights can be part of a complete solution for riding in less-than-ideal lighting conditions, but they shouldn’t be your whole solution. Because it’s difficult for drivers to judge distance and speed based on a flashing light alone, consider using two lights, one flashing and one not.

If this isn’t an option, see if you can find a light that pulses rather than strobes. This type of flashing behavior means that the light will be on for more time and will be less distracting to other people on the road.

An additional point to consider when purchasing a light for your bicycle is the brightness. Modern LEDs are getting incredibly efficient and cheap, meaning you can get bicycle lights that are bright enough to temporarily blind oncoming traffic. If you find yourself cycling in an area where it’s especially difficult to see, make sure that your extra bright lights are angled down, like a car’s headlights.

This way, you’ll be able to see in front of you with less risk of distracting or impairing the vision of other people on the road. If there are streetlights where you cycle, however, consider simply sticking to more reasonable lights that won’t blind people who look at them.

For comparison purposes, a car’s headlights often output about 700 lumens each. If your lights are approaching that brightness, treat them like headlights and make sure that they’re angled downwards when they’re turned on at full blast.


As humans, we’re prone to pay more attention to flashing lights than steady ones. Some bicyclists take advantage of this fact to ensure that they stay extra visible on the road, especially during mornings, evenings, and nights. This can be a good idea, but you’ll probably find that it shouldn’t be your whole night-riding safety package.

Bright clothing, a high visibility vest, and a combination of both steady and flashing lights will be much more effective at helping drivers, cyclists, and even midnight pedestrians know where you are than a flashing light alone.