I'm not sure why nobody thought of this, but I think self-driving cars should have some special lights or signs that show the world around them that they are se

I'm not sure why nobody thought of this, but I think self-driving cars should have some special lights or signs that show the world around them that they are self-driving. That would at least lessen the frustration of drivers behind when it is reluctant to turn into oncoming traffic, or acts like a drunken driver.