In 1962, during the extensive construction of the Interstate Highway System, Temporary Interstates were marked as a way to connect two completed freeway sections of Interstate highways.
The Temporary Interstates were signed on mostly surface roads that did not meet Interstate standards. The shields were red, white and blue with the word "TEMPORARY" appearing in the top quarter instead of "INTERSTATE." Most of the Temporary Interstates would later be replaced by Business Loops, such as Temporary I-85 southwest of Greensboro, North Carolina (also signed as US 29, US 70 and, at its southern end, US 52).
Future Interstates, such as I-86 in New York, have become more common in recent years. The shields have "FUTURE" in the top quarter, and are placed along what will eventually become the alignments for the mainline.