In 2004, Bellevue, Washington, added a grippy surface to a downhill intersection after warning signs failed; crashes fell 78% and crash costs fell 83%
Signs, lights, and markers did not fix a downhill intersection in Bellevue. A grippy surface added in 2004 cut crashes by 78% and crash costs by 83%.
We haven't written up this one. Hindustan Times - World News has the full story — the link below goes straight to it.