Houston does the same with its highways, and, in fact, they have different names depending on their relation to downtown. For example, I-45 is both the Gulf Freeway and North Freeway, 59 is both Eastex and Southwest.
Austin also has named highways (Mopac, Capital of Texas, Research), except I-35, which I was once told was because "it was the only one not created locally."
Austin also has named highways (Mopac, Capital of Texas, Research), except I-35, which I was once told was because "it was the only one not created locally."