tommarmstrong

Sydney makes extensive use of no left/right turn between 6-10am/3-7pm signs. It makes sure that traffic stays on the main roads instead of side streets that would quickly fill up during peak hour otherwise but isn't an inconvenience outside of those times

I found an article that has a little more info but also an interactive demo of why they're hard to forge

http://www.fsd.it/usefuldesign/german_plates_font.htm