Interstate is Tobias Frere-Jones's 1993–99 typographic reinterpretation of Highway Gothic — the FHWA Series letters Theodore Forbes drew in 1949 for US road signs. This system reads a guide sign directly: a flat field of retroreflective green carrying crisp white lettering, exit tabs, arrows and route shields.
The vocabulary is functional, not decorative. Wide apertures, rounded-square terminals and generous tracking keep legends legible at speed. Colour is regulated by MUTCD convention — guide-sign green, warning amber, regulatory red — never expressive. Everything is matte, borderless-clean and built to be read, not admired.