I-275 (MI), while signed north of I-96, does not technically exist north of I-96.
Highway 99 in Washington, may or may not be part of SR 99. In Everett/Lynnwood or near Seattle/Tacoma: Yes. Vancouver: No. Anywhere else: No.
International Boulevard, in front of Sea-Tac Airport, and a continuation of the pavement of SR 99, in not in fact part of SR 99.
Regardless of what the locals call is, M-24 in and round Lake Orīon, MI, is not Lapeer Rd. It is actually either Broadway or Park, depending on the segment. Outside of Lake Orīon, it is Lapeer Rd. Which is doubly confusing, given that there is a Lapeer St. in downtown, not connected to M-24. Also, M-24 never connected to US-24. US-24 doesn't come close enough, and when it could have, it was signed as US-10 at that time.