Same green sign, different rules in every state
California law says the sign at a city limit has to show three things: the name of the place, its population, and its altitude.
The federal sign manual says the same sign should "display only the name." Both of those are on the books right now.
That's how road signs work in this country. Washington writes the manual, each state adopts it with its own changes, and the green rectangle at the edge of town ends up meaning something a little different depending on which state line you just crossed.
California counts and measures
The rule is in the state's Streets and Highways Code. On every state highway, at the limit of each city and each unincorporated town, there's supposed to be "a uniform road sign which sets forth the name of the city or town, its population, and its altitude."
California's edition of the manual even says where the numbers can come from. Population can be taken from the federal census, the state Department of Finance, the county board of supervisors, or the county planning commission. Four choices, and they won't all agree.
The elevation is looser still. It "may be that of the courthouse, post office, railroad station, or benchmark in the central district of the city." So the number on the sign into Truckee is the height of something downtown, and the state doesn't much mind what.
Colorado and Missouri dropped the headcount
Colorado's standard sign shows the town and its elevation, and leaves the population off entirely. In Leadville, that's the number worth bragging about anyway.
Missouri used to print populations and quit. The signs already standing keep their numbers until they wear out. The new ones get the name and CITY LIMIT.
Wisconsin made the number a sticker
Wisconsin still posts populations, and its sign catalog has a detail we like a lot. The population number is listed as its own item: a decal.
So a new census doesn't have to mean a new sign. The number can change and the sign can stay. Missouri stopped posting populations rather than redo them all for a new census. Wisconsin's catalog has a sticker for that.
The same catalog has a version of the sign for places that never incorporated, marked UNINCORPORATED. That's at least honest.
Ohio tells you when you leave
Most states mark the way in. Ohio's supplement to the manual also provides a LEAVE CORP sign for the spot where the road exits a municipality, and an ENTER CORP sign for where it wanders back in. CORP is short for corporation, as in the incorporated town.
Both come in a twelve-inch size for places with no room. A foot-square sign telling you that you've left Marietta is a very Ohio amount of thoroughness.
Massachusetts isn't even green
On a lot of Massachusetts roads, the sign at the town line is white and shaped like an open book. It says ENTERING, the name of the town, and the year the town was founded.
So in a lot of the country the sign tells you how many people live here. In Colorado it tells you how high up you are. In Massachusetts it tells you how long the town has been around, and in Salem that's a number with some weight to it.
What nobody's allowed to add
The federal manual does draw one line for everybody. No elected officials' names on the boundary sign, and no "promotional messages, such as notable accomplishments or claims."
State welcome signs get a pass. Those can carry the state motto and the governor's name, and Wisconsin's catalog lists a governor name plaque as a separate part, on redwood. Governors change. The plaque unbolts.
It's the same sign until you read it
From the driver's seat they all look alike. Green, white letters, gone in a second and a half.
Slow down and each one is answering a different question. How many of us are there. How high up are we. How long have we been here. Every state picked the one it thought mattered, and put it on a sign with your town's name over it.