I don't think it's a bad idea in theory, just bad in execution. Words written in the same style that appear to be sticking up 3D on the road would have the same effect. It would cause the driver to focus to read the words without the above mentioned confusions.
They had "Watch for children" signs for many years. Snow cannot cover them.
Words are good, but they say a picture is worth one thousand words. The safety people are too polite to say it, but I think it is shock treatment. Like when they tow wrecked cars to conspicuous places just before prom nights.
Reminds me of when they used to make us watch "Red Asphalt" and the other gory old films. "Mechanised Death" was another. They were not meant to reason with drivers, just put a fright into you. And they did!

They sure made me slow down and fasten my safety belt ( long before it became the law )
Looking back, I guess now, most people would just laugh, but back then they had quite an effect on us.
"She is a project of the West Vancouver police and the Community Against Preventable Injuries — preventable.ca — which promotes public safety."
"Skeptics may wonder if the optical illusion could itself contribute to an accident. Bob Dewar, a psychologist who specializes in driver behaviour and traffic safety, said, “If [the image] really does look like a child, someone may slam on their brakes and get rear-ended or they may swerve to avoid this child that isn’t really a child.”
David Langmuir, the principal of Ecole Pauline Johnson, said that was his initial response, too, but he has become a backer of the plan.
“The image appears very gradually,” Langmuir said. It is most realistic when seen from about 100 feet away, but “then the realism of that image declines rapidly as the driver gets closer.”
After the optical illusion has been in place for a week, police, traffic engineers and parents will provide feedback to determine whether it improves driver safety.
“It’s important for drivers to expect the unexpected,” Dunne said.