What Are These Strange Signs In My Neighborhood?

There are four of these strange, eight sided signs in my South Salt Lake neighborhood and they're placed on the corners of the 4-way intersection. I know have to mean something, maybe it means STOP, as in bring your vehicle to a complete stop before proceeding. No that can't possibly be what means. 

Ugh, over the weekend my wife and I counted 5 drivers blowing through the 4-way stop on Saturday alone. Come on people!

School Bus Stop Sign
Aaron

title

Content Goes Here