that's right mod qroon.
problem is walang law about it, nor is it a hard written rule in driving because for the most part of vehicle operation, we can't really regulate it.
it's going to be like regulating against the use of heel-and-toe shifting because of the noise it makes through the exhaust
tama ka dyan, regulating the use of blinkers during low visibility is like trying to regulate parking and making it mandatory that all cars should park facing the wall. and in the spirit practicality, you really can't apprehend people when it happens, just like you can't penalize people for not being calm and orderly when there is a fire in a building.
I think it will help though, to include it as one of the more "major" infos we teach as the norm, just like the numerous rules of thumb we learn when starting to drive. I think it's something we can change as part of the motoring community, let's not even expect the [strawberry] in our government agencies to make this change. After all, it does concern safety, and IMO it is as equally debatable as defensive driving