These are fonts for designing actual street, highway, and freeway signs in the United States, and are based on public domain outlines in the FHWA Standard Highway Signs manual.
They have been designed on a 10,000 Em square in order to accurately fit the width of words to a 1/1000" spec. based on the tables in the Standard Highway Signs manual, when set at 504 points (5.6" height) in Adobe Illustrator. Words can be scaled up or down to the specified letter height and maintain a high degree of width accuracy.
Additional letter spacing for signs in the US is determined by percentage, and not in the manner used by software ("tracking"). Separate fonts are provided for spacing up to 50% positive or negative, and the -100 and plus 100 fonts can be used to blend with a +50 or -50 word to obtain 60, 70, 80% above or below.
No kerning tables are provided, because no kerning is (officially) used in the production of street signs in the US.
I hope these come in handy for those in the industry and for those who find highway signage fascinating.