(I'm not claiming to be local to Dallas, but thought I'd point this out.)
Most folks know that odd-numbered Interstate Highways run North/South. I-35 runs through Dallas, and through Fort Worth. If you fly into DFW, your travel will likely run along part of I-35. Here's the kicker: I-35 splits just north of Hillsboro, and two branches run north to Denton. The branch through Dallas is I-35E, and the branch through Fort Worth is I-35W.
Moral: Don't panic if you're going South on I-35E.