Font Family: Interstate Pi, Number of fonts: 4*TTF, Type Foundry: Font Bureau, Designer: Guy Jeffrey Nelson, Design date: 1994
These four pi fonts contain the basic set of highway signs, with their symbols, to properly support literal use of the Interstate family. Auxiliary solid forms allow for rendering in color, as well as black and white.
The first three sets address U. S. Federal Highway Administration categories: Directional, Regulatory, & Warning. The fourth explores an official Font Bureau category: Humor.
All four were digitized by Guy Jeffrey Nelson.