Tobias Frére-Jones designed the font Interstate back in 1993. Today the Interstate is widely spread and often used for internetdesigns.

Interstate is based on the signage alphabets of our [USA] Federal Highway Administration, letterforms absorbed at a glance everywhere we drive. Interstate provides a real edge in swift communication. (Font Bureau)

Interstate consist of 40 styles. Who can not afford buying it or only uses the font once can use its clone Blue Highway by canadian type designer Ray Larabie. 4 styles are available.
“Download it from Typemotion.de.
Please note: Blue Highway needs a good kerning.