I live in NC, but every state I’ve ever traveled through seems to work this way: say you see a sign saying “Richmond 10.” But you actually enter the city limits waaaaaay before that. I guess it could signify the distance to the center of the town, but that doesn’t always seem right either. Any idears?
The centre can change as the boundary shifts. Most places use a more permanent landmark common to most towns like a cathedral, courthouse, main post office or the townhall being the most obvious.
Both Paris and Madrid have a “Kilometer Zero” marker from which all distances to the rest of the country is calculated. The one in Paris is located very near Notre Dame cathedral . In Madrid it is located in the Puerta Del Sol. I imagine other capital cities have similar markers. Does anyone know where the London one is located?
The zero point for London is Charing Cross.
The Zero Milestone for the US is located between the White House and the Mall.
I don’t think Norway is organized enough to have such a thing 
There is a monument in Capitol Square in Richmond that is the point from which distances to Richmond are measured.
For most cities in the US, the distance is measures from the city hall or main post office.
[nitpicky question]
Does that include getting off the freeway, riding around the cloverleaf, and driving to the landmark on surface streets?
Or is it mile (or km) 0 when you drive past it on the freeway?
[/nitpick]