Add a new car turn signal for “continuing straight ahead”—why does this not already exist? A simple update to your car’s “CHMSL” (which is apparently a thing it has).


Drivers can signal their intent to turn or change lanes by using their turn signals (A.K.A. “blinkers”). Currently, a driver can express two concepts with these signals:

  1. “Left”
  2. “Right”

The Issue:

Sometimes, a driver’s might want to express a third concept:

  1. “Not turning” / “Continuing straight ahead”


The left and right brake lights are both accompanied by a yellow “turn” light and white “reverse” light.

But there’s a third brake light, too—in American passenger cars manufactured after 1986, cars have a centrally-positioned elevated brake light with the easy-to-remember name “center high mount stop lamp (CHMSL).” (This light is believed to prevent about 1 in 25 collisions that otherwise would have occurred. Not bad!)

Unlike the other brake lights, this center light is completely alone, thus presenting the opportunity to add a yellow “go straight” light to this center light (Figure 1).

Fig 1: With this third “turn” signal, located above the previously-described “CHMSL,” the driver can now explicitly indicate that they are not turning. Amazing!

Future Work:

It’s not obvious how a driver would activate the “not turning” signal. Intuitively, one might suppose they could push the turn signal stalk (lever) forward, but usually this has been repurposed for wipers / cruise control / high beams.

Based on the 2015–2020 trend of car user interface changes, I suspect the UI / UX designers will put the control on a touchscreen button a few levels deep in a menu. Drivers are (apparently) believed to love that sort of touchscreen-only interface—it’s so clean, with no distracting controls ruining the sleek lines of the dashboard!

PROS: Adds new signaling options, thus bringing a richer driving experience to car aficionados everywhere.

CONS: This idea might be totally pointless—is there any situation (even a contrived one) where a driver would actually want to convey “not turning”?

Cross-reference: this idea is related to June 8, 2015’s proposal to distinguish between turn signals and hazard lights in certain conditions.