Good question....
The AK DOT mapped all these points out.
They provide such on their website.
https://data-soa-akdot.opendata.arcgis.com/datasets/0415461584a349e5b9a772c1835ebe75_0/explore
A friend led me to the main page and it took some digging to get to this.
Downloaded the CSV, imported to MySQL and created the SQLlite DB with table.
I have been asking for this data for years, and now I can create the project with such data. I don't live in AK, Kamloops BC is where I reside.
Without such data, the only other way is to DRIVE each road and tag mile posts (with an app) manually...
I shall post the completed app when done. It's pretty funcky...