Flashing lights and bikes have become like love and marriage – they are strongly associated together, but there CAN be problems. When should you flash your bike lights, and when is it not a good idea? Here’s a guide to when to use your bike lights on flashing mode.
Most Bike Lights Offer a Variety of Modes
Most good quality bike lights have a range of modes, including steady and flashing. On any given night where there are a lot of cyclists out, you will see both white (front) and red (rear) bike lights flashing all over the place. This video taken on the Burrard Street Bridge in Vancouver shows a whole stream of cyclists – and every one either has flashing lights, or no lights at all.
Flashing lights seem to be the most popular choice – but not every one loves them. In fact, there are times when they should not be used, or should be used only with care not to disorient others.
Live and Learn …
For the longest time I thought that as long as there was sufficient ambient light for me to see the ground, I should always use a flashing light rather than a solid light. Why? Because a flashing light grabs attention, and saves on battery power. So, I would only switch to steady light mode when I was trying to see the road and watch out for potholes.
Well, I have learned over the years that there is more to it than that.
Flashing bike lights are attention grabbing, BUT …
So, here is the key problem with flashing bike lights – when people see a flashing light at night, it is hard for them to judge how far away it is, and how fast it is moving. This means that a motorist may misjudge where you are, and that is NOT good.
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Worst-Case Scenario with Flashing Bike Lights
We have actually had the worst-case scenario of this. A man driving an F-150 on a broad, empty road drove CLOSER to my wife (Maggie, Mrs. Average Joe Cyclist) because he was curious about what her flashing bike lights were! He got so close that his side mirror clipped her shoulder. At the time, she was a small woman in her fifties. This man’s curiosity could have killed her.
Luckily, it was a newer truck, so the mirror gave way. That, combined with Maggie’s forward momentum at the time, saved her from serious injury. She was also able to stay upright, rather than falling under his wheels. Still, she did need several months of physiotherapy to get her shoulder right. Luckily, she just got right back on her bike, and was not scared off. I am not sure I would have been as resilient …
I have to add that the motorist was horrified at the results of his actions. He stopped, and insisted on transporting Maggie and her bike to her office. He also stopped by the next day to make sure she was OK. So, he really was not a bad person. He just could not make sense of flashing lights on the side of the road …
We Need to Make Sure Others Can See Us
Fortunately, most motorists are not that stupid. Still, we do need to make it as easy as possible for other road users to know where and what we are, and how fast we are moving. Not just motorists, but pedestrians and cyclists as well. As a cyclist, I appreciate when I can see other cyclists coming towards me.
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Recommended best practices for how to use flashing bike lights
To that end, these are our recommended best practices for how to use flashing bike lights.
How to use your front bike lights while cycling at night
You should not cycle with only a very bright, flashing front bike light
This choice will make it hard for oncoming road users to judge where you are and how fast you are coming at them. If your flashing bike light is 300 lumens or brighter, it may even seriously disorient people.
Some people really HATE flashing lights
In fact, since I first wrote about this issue, I have had interesting feedback from many cyclists about the problems of flashing lights: It seems that they were invented when bike lights were much dimmer than they are now. But now we have ultra bright LED lights, sometimes as bright as 3,000 lumens.
Many cyclists experience disorientation, headaches, migraines, and nausea when 3,000 lumens of flashing LEDS are coming straight at them.
If used on a multi-use sidewalk with pedestrians, flashing lights have no real purpose, and merely inflict discomfort on pedestrians. As one reader eloquently expressed it: “We pedestrians are hard pressed to cause cyclists harm and the (often bright) strobe lights are pretty painful and annoying.”
So for the sake of your fellow cyclists and other people too, please be very careful about how you use flashing lights, especially if your lights are very powerful.
The best bet for flashing bike lights is this:
Try to avoid using a flashing front light at night. A steady light is clearly visible at night, and does not hurt and disorient other people (unless it is excessively bright and aimed at their faces).
If you must have a flashing light, use one not-very-bright flashing bike light (not more than 300 lumnens) PLUS one steady bike light. The steady light helps you to see where you are going, and also makes it much easier for oncoming road users to judge how far you from them, and how fast you are approaching them.
NEVER use them while on a sidewalk that is multi-use – that is, also has pedestrians on it.
A good choice of a flashing bike light for night time cycling is one that has a pulsing light, rather than a strobe light, such as the Light & Motion Urban 350 (reviewed here).
Try not to blind other road users!
As always with lights on any kind of vehicle, make sure that your bike lights are not angled in such a way that they blind oncoming road users. This is unsafe for them and for you, and can cause collisions or road rage. Bear in mind that a single car low-beam headlight is about 700 lumens. With so many bike lights now offering 700 lumens and more, it is very easy for cyclists’ lights to blind other road users.
Related Post: Best Budget Bright Bike Headlight – Our Lumintrail Review
My personal favorite is my LuminTrail (reviewed here), which I wear mounted on a helmet. The mount has a lot of flexibility, so I can angle the light just right for the conditions. Also, because it is on my head, I can quickly turn my head away from someone if need be. Whenever it is on its full 1000 lumens power, I angle it straight down at the road. I really love this bike light because it is so bright and versatile. It is also my go-to light for camping, when I use it with a head strap.
How to use your front bike lights while cycling in the daytime
First of all, yes, I definitely advise using bike lights in the daytime. It seems that this is uncommon, which I find odd. I once spoke with a bus driver who told me that he loves cyclists with day-time lights because he can see them from a block away, whereas without them, he found it hard to spot cyclists until he was uncomfortably close to them. That sold me! Anything that makes me more visible to people driving giant vehicles that could kill me is good with me.
However, no matter how bright your bike light is, it is going to be hard for other road users to notice it in the daylight while it is on steady beam. Therefore, daytime is definitely the time to flash those bike lights! All the same, do check that they are not so intense that they manage to cause disorientation and pain to others, even during the daytime.
In the daytime you don’t have the problem of other road users’ not being able to see how far away you are and how fast you are going, because you are visible.
The other benefit is that your bike lights will last longer in flashing mode than on steady.
How to use your rear bike lights
The same principles in general apply to rear lights, expect that these lights are usually less bright, and are much less likely to cause discomfort and disorientation to other road users. In general, your best bet for maximum visibility is to have two rear bike lights (one steady and one flashing) at night, and at least one flashing rear light in the daytime. If you don’t have a rear light, start with a highly rated one, such as the Cygolite Hotshot.
Side Bike Lights
I also highly recommend side bike lights so that you can be seen by road users approaching from the side. Monkeylectric lights (reviewed here) are high quality, long lasting, bright and fun. They attach to your bicycle spokes, and can be programmed with various flashing combinations and patterns – such as flashing green and red stars at Christmas time! Of course, these lights flash all the time. However, they cannot blind or disorientate other road users, as they consist of tiny LED lights, and of course they are not facing forward towards oncoming road users.
Below are links to all of our best posts on bike lights!
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I was rather surprised to see no mention of the Garmin Varia rear light/radar system, particularly given all the Garmin Edge content on your site. I absolutely love mine, but would be curious to hear how motorists feel about the variable pulsing patterns that change with trailing vehicles’ approach distance/speed.
Average Joe Cyclist says
Good point. I will do some research on that and add it in. Thanks Bill!
Can you add a section on flashing lights on shared walkways with pedestrians. We pedestrians are hard pressed to cause cyclists harm and the (often bright) strobe lights are pretty painful and annoying.
Average Joe Cyclist says
Sure, I can do that. I know that is also a big problem.