Uh, why should the lifespan of a roadsign be only ten years? Unless they're really, really shoddily manufactured?
It could be that the printing of the name on the background takes a beating and the letters either darken or peel off.
Their deadline is two years less (20%) than the average longevity of a street sign. That hardly makes it a case of replacing the signs as would be normal.
The rule wass adopted in 2003, meaning cities and states were given 15 years to change signs with lifespans of 10 years.
