[ColFrancis]

I've noticed a lot of turns at traffic lights are getting explicit red arrows. A solid green light without an arrow means that you need to give way to pedestrians and other vehicles if turning. It feels to me no one is looking any more, they just think green means go. I think it's because we've trained them out of thinking with too many constraints.

[flyinghamster]

I see them in my area, too, but only at intersections with any or all of extremely heavy traffic, poor sightlines, or multiple left turn lanes, that would make a left turn on plain green dicey at best.

Sometimes there will be red, yellow, flashing yellow, and green arrows, with flashing yellow being the yield option, used at times of day when it's appropriate.

[HWR_14]

My guess is that it's more a matter of cost. With LEDs, it's cheap to have a red arrow and a red circle. With incandescent lights, you cannot just illuminate part of the red bulb to get an arrow.

[californical]

Except that none of the traffic lights that I’ve seen have ever used the same light for an arrow and circle — even with LEDs, it’s always two separate lights

[HWR_14]

Really? That seems costly for no reason. I thought when I've seen it it's been the same light.