Electronics, Lighting, & Gadgets - Red vs. Yellow tail light

I have a planet bike superflash and planet bike yellow blinky:

http://bicyclehabitat.com/itemdetails.cfm?id=11373

From a distance the yellow blinky is far more noticeable than the superflash. Is this because yellow is a lot more visible due to the wavelength issue compared to red?

The law says you have to have a tail light, and that taillight has to be red, and visible from a specific distance (usually 500 feet or so).

Now, Yellow or amber reflectors are more visible at a distance, and many cyclists have added amber reflectors to increase their conspicuity at night.

But be sure you have at least one red tail light or reflector.

I have a planet bike superflash and planet bike yellow blinky:

http://bicyclehabitat.com/itemdetails.cfm?id=11373

From a distance the yellow blinky is far more noticeable than the superflash. Is this because yellow is a lot more visible due to the wavelength issue compared to red?

The amber light was meant to be used on the front of a bike, not the rear.

The law says you have to have a tail light, and that taillight has to be red, and visible from a specific distance (usually 500 feet or so).

Now, Yellow or amber reflectors are more visible at a distance, and many cyclists have added amber reflectors to increase their conspicuity at night.

But be sure you have at least one red tail light or reflector.

That's why I have both on the rear . I see many vehicle with yellow lights on their sides, i.e school buses and trucks. Is there a situation where a yellow rear light would be confusing?

To the OP,
Yes, yellow is due to wavelength.

In NYS:


Section 1236. Lamps and other equipment on bicycles.

(a) Every bicycle when in use during the period from one-half hour after sunset to one-half hour before sunrise shall be equipped with a lamp on the front which shall emit a white light visible during hours of darkness from a distance of at least five hundred feet to the front and with a red light visible to the rear for three hundred feet. Effective July first, nineteen hundred seventy-six, at least one of these lights shall be visible for two hundred feet from each side.

That's why I have both on the rear . I see many vehicle with yellow lights on their sides, i.e school buses and trucks. Is there a situation where a yellow rear light would be confusing?

Yellow lights are running lights or corner lights. Motorists have been trained to associate certain colors with certain functions, i.e. red lights to the rear, white light to the front, yellow to the side. It's best not to get too far outside the norm or you'll confuse other road users. Confusing other road users can have both good and bad repercussions. If you can make them ask 'WTF is that thing coming at me?', that's good confusion. If you make them ask 'Is that a bike going away from me, coming at me or where the hell is it going?', that's bad confusion. Bad confusion can result in having your third dimension invalidated. That's never good and is usually painful;)

Bottom line: Lots of white light front, lots of red light rear.

It is legal for a car to turn on their flashing yellow danger lights when going slow . Why can't the same logic extend to bikes ? That's why I think a red and yellow light are appropriate.

It is legal for a car to turn on their flashing yellow danger lights when going slow . Why can't the same logic extend to bikes ? That's why I think a red and yellow light are appropriate.

People do it but I don't know if it's legal or not. A flashing red gets peoples attention because we are taught (I'm teaching my daughter now:() that red usually means Danger! or 'something is happening that needs to be paid attention to'. A flashing yellow could mean 'watch out!' or it could mean 'I'm going to make a turn.' or 'I'm an old fart who forgot to turn off my signal indicator.":innocent:

It's also not directional. From the driver's perspective, a red light means that you are overtaking someone. A white light means they are coming at you. A yellow light can be found on both ends of a vehicle and in the middle. How is a driver to know where you have it mounted?

You are using a red light to the rear...which is good. I'd just stick with more red lights... some steady and some flashing...on the rear.

Bad confusion can result in having your third dimension invalidated.

That's an awesome quote. I'll cite you if I use it.

People do it but I don't know if it's legal or not. A flashing red gets peoples attention because we are taught (I'm teaching my daughter now:() that red usually means Danger! .

Most Japaneese and European cars use yellow for the turn signal. So when you turn on your danger/hazzard lites, you see a a pair of flashing yellow lights. So a bike can just also use flashing yellow to indicate caution. I suppose ideally you would want a pair of flashing yellow lights. But since we don't normally carry a pair of red lights, that is not so important...

My reason for liking yellow lights is it is a lot more visible from a distance than red. I see your point that it could lead to confusion about whether you are a turning car.

Bigger picture: make sure your SuperFlash is actually aimed dead-level, not pointing up or down. It's got a pretty focused beam, so you want to make sure the hot spot of the beam is actually aimed where the motorists will be.

That's why I have both on the rear . I see many vehicle with yellow lights on their sides, i.e school buses and trucks. Is there a situation where a yellow rear light would be confusing?

Flashing yellow almost always indicates something to be extra cautious around. For example, construction vehicles, equipment and markers have flashing yellow lights. The slow moving parking enforcement cars have similar lights. A flashing yellow light to the rear seems appropriate if you are moving slower than the prevailing speed of traffic which is almost always true for a bike.

It's best not to get too far outside the norm or you'll confuse other road users. Lots of white light front, lots of red light rear.

I believe that motorists are used to following red lights, and avoiding amber lights. Amber is used for construction/pothole markings as well as on the back side of most ambulance vehicles (along with flashing red lights).

Somebody really drunk might just follow your steady red light or reflector - him at 50 mph, you at 15 mph. Not pretty.

I run a blinky amber and a bilnky red on the rear. In my rear view mirror I can see cars moving out of my lane an eighth of a mile back. I would never run a steady red light or a red reflector alone. Blinky red alone? Do I really want to ID myself as a bicycle if there is a chance I could look like a BUS? Not really. Be the bus Danny!