My favorite FAQ about the US Interstate System

Many of you may not visit the "Frequently Asked Questions" webpage of the US Interstate system, but you should. Let me know if you think people frequently ask these questions. I suspect there really are a small and devoted group of people who keep the FHWA busy with the following:

I-99 is out of sequence—what can be done about it?

Although State and Federal officials normally select Interstate route numbers, Congress made the choice of "99" for upgraded U.S. 220 in Pennsylvania. Section 322 of the National Highway System Designation Act of 1995 states that the specified section of U.S. 220 ". . . is designated as Interstate Route I-99." Therefore, only a statutory revision can change the number.