Little Green Signs

If you travelled through Vermont on its state highways, you probably noticed tiny green signs along the roads with a bunch of numbers on them. They look like New York's reference markers, and they serve a similar purpose. What do all the numbers mean? Perhaps you figured out the top line is the route number, and mostly, you'd be correct. The markers always have 3 lines with 4 numeric digits on each line. Here's how to interpret them.

First line: The top line identifies the route. If on a numbered state maintained route, the first 3 numerals are the route number. Zeroes are added on the left, if necessary, to make the number 3 digits. The fourth is a zero, unless the route number has a letter suffix. If the route number has a letter suffix (the "A" in Route 22A), the letter is converted into a number (1=A, 2=B etc.)

So a marker along Route 100 will have 1 0 0 0 on the top line, one on Route 67A will have 0 6 7 1 and so on. As the vast majority of these markers are along state-maintained numbered routes, nearly all of the ones you'll see fit this description. However, the first line could also be a Functional Class number. These are numbers assigned to more important town roads as well as Named State Highways. The numbers 0000-0499 are Major Collectors, 0500-0999 are Minor Collectors, 9000-9999 are Named State Highways. Named State Highways are short state-maintained routes witout a posted route number, often connectors from an interstate interchange to a major road nearby. Also, some 'bannered' US routes which don't fit into the normal numbering system such as Business US Route 4 and ALT US 5 have four digit numbers starting with 999.

The vast majority of these don't have the markers, but a couple of the Named State Highways have them. Also, sometimes you'll be on a state numbered route and see a marker whose number doesn't match the route number. This is because the road is a town highway, not state-maintained despite the state route number, and the number on the marker is the Major Collector number, not the route number.

Second line: This is the political location. The first two digits correspond to the county in alphabetical order, the second two digits represent the town within the county, again in alphabetical order.

Third line: The last line is the length in miles from the previous town line or the beginning of the highway. There is an implied decimal point between the second and third digits. Whenever the road crosses a town line in the northerly or easterly direction, the second row numbers change and the third row resets to 0000. An exception is when the highway crosses into a town it was in previously, in that case the mileage picks up where it left off when it left the town.