When were emergency flashers required on cars?

Question

ok smart boys. I know why they are used.

I want to know what year NY made them manditory on all cars.

Answer 1

Emergency flashers alert drivers that another vehicle is either stopped or moving slowly ahead—whether on or off the road.

When flashers are enabled, all four turn signal lights flash at once.

If your vehicle breaks down, use your emergency flashers and move off the road as much as possible—too many wrecks occur because drivers could not see stalled vehicles until it was too late to avoid colliding with them.

Answer 2

I believe sometime in the 1950's era, not positive but Ive had early 50's vehicles and they did not have them and have ended up with later 50's vehicles and they did.

Answer 3

when emergency happens?