Q&A - Flashing Rear Lights for Bicycles

Q&A ImageI see more and more cyclists with flashing rear lights. Is this actually a better option or is it just a fad? Would like to know what the law is and if there is any research on the effectiveness of rear flashing red lights as opposed to lights that are just on all the time. Personally, I find them distracting and more difficult to pin point where exactly the bike is and more difficult to judge it's speed compared to a light that is not flashing. If flashing rear lights are more effective why don't all cars have flashing rear tail lights?

Let's take a look at the law for a start:

Rights and duties of operator of cycle

183 (6) A cycle operated on a highway between 1/2 hour after sunset and 1/2 hour before sunrise must have the following equipment:

(c) a lighted lamp, mounted and visible to the rear, displaying a red light.

(7) Despite any other provision of this Act or the regulations, a cycle may be equipped with a flashing red light.

Flashing lights do draw a driver's eye, and this may or may not be a good thing. As you observe, the drawing of attention is desirable, but the vehicle tends to move toward what the driver is looking at. It is also true that it is easier to track an object with a steady burning light. Perhaps the cycle should be equipped with both?

The best study that I can find on bicycle lighting is from Europe: Requirements on Lighting (Light Intensity) and Reflectors of Bicycles

In reply to by DriveSmartBC

pg 30 and 31 from the European study you recommended seems to have confirmed my belief that flashing rear lights are actually less effective and potentially dangerous.

"In summary it can be concluded that flashing bicycle lights are not necessary for agood conspicuousness. .........  From the rear, the flashing lights do not bring anyadditional benefits and in fact in rural areas even leads to a decrease in conspicuity.Flashing also has the following general disadvantages:ï‚· it may confuse others, for example confusion with the lights from an emergency vehicleï‚· it may irritate othersï‚· It makes other traffic participants less visibleï‚· It makes it hard to judge the distance and path followed by the cyclist So, there seems little use for flashing and certainly should not be promoted."

interesting how people get caught up in fads and manufacturers make things to satisfy the fads rather than promote safety. As more and more people are riding bicycles there's going to be a lot of confusion with all those flashing lights, especially in busy places like Vancouver. I wonder what percent of riders are using them. Next time I'm in Vancouver I'll do a count.

In reply to by Anonymous (not verified)

Interesting. I've owned one of these flashing LED bike lights for over 20 years. Battery life is a benefit. Two AAA batteries are rated for 100 hours flashing, but only 30 hours in the steady mode.

I can agree that flashing red lights tend to draw the driver toward them. This was researched several years ago in the U.S. as well and consequently ended with the blue lights being used on police vehicles. Personally I would rather see a steady red light displayed at the rear of a cycle but I must give credit where credit is due and compliment cyclists that do use an illuminating device when cycling. Even a flashing red is better that no light at all.