Chet Skwarcan is an award-winning engineer, writer, and industry innovator in the field of traffic engineering. He is known for leveraging his creativity, logic, and technology to solve today’s engineering challenges.

Left Turn YIELD on Flashing Yellow

Yep. Sometimes however, a flashing light simply indicates a loose bulb. Turn off the light and after it cools, carefully tighten the bulb and turn it back on. By the way, why are you even using a yellow bulb? That’s kind of strange – just stop it.

However, there IS perhaps a more familiar type of flashing yellow light – and it’s associated with the transportation industry. The flashing yellow light I’m referring to is the one on your dash. The one shaped like a triangle with an exclamation point inside. And (or, so I am told), that after a few weeks it starts to beep and eventually turns red, and then you’ll smell smoke (or possibly see flames — or, so I am told). This flashing yellow light indicates one of two things, 1) you’re almost due for an oil change or, 2) your engine is about to explode. Fortunately, most auto mechanics possess the wizardry to decipher which outcome is most likely – it’s called an RDG device (random diagnostic generator).

And you probably won’t believe this, but, as pictured above, there is yet ANOTHER example. And interestingly enough, it too has to do with the transportation industry — traffic signals in particular. And because I are a traffic engineer, this was too much of a coincidence to ignore. Let me explain…

Specifically, this flashing yellow light is arrow-shaped and incorporated into existing traffic signal heads. You may have noticed some recent excitement amongst nearby cities and towns regarding something called FYA’s (flashing yellow arrows) because, according to an anonymous city employee, “Traffic signals can use a little jazzing up – plus, takes your mind off the roundabouts”.

Hopefully, this traffic signal modification satisfies man’s desire to change things, at least for a few years — long enough for autonomous car technology to render traffic signals themselves unnecessary (tip: do not invest in traffic signal equipment).

So, when you see a flashing yellow arrow, memorize what it means (because taking the time to read the an instructional sign may make you late for something). And it simply means this: Proceed with making a left turn AFTER yielding to oncoming traffic and pedestrians.

Flashing yellow arrows actually improve intersection efficiency, particularly when traffic is light. And a national study has demonstrated that drivers found flashing yellow arrows more understandable than traditional “yield-on-green” indications.

Now this does transfer a bit more of the decision making back to the driver, so be careful. Yield to oncoming traffic and especially beware of pedestrians before you initiate your turn (note to pedestrians: painted crosswalks do not make you invincible).

Chet Skwarcan, Traffic Engineer and Futurist, has over 20 years of traffic engineering experience solving (and preventing) traffic problems and can be reached at