If you are in north TX and you hear traffic reports on the radio with...
* "Decatur Cutoff", refers to US 287 (the US 81 part is rarely if ever mentioned) in north Fort Worth NW of its split from I-35W. AFAIK, that part of US 287 has never had a local name, and I never saw anything that looked like a named street blade sign the few times I've been out that way. So, I'm not sure where the "Decatur Cutoff" name comes from, but traffic reports are the only source you'll hear it from.
* "Fair Park Curve", is a long S-curve along I-30 east of downtown Dallas in the vicinity of Fair Park. There is no street or freeway naming as such (the freeway is East R.L. Thornton Freeway, for a late Dallas businessman/banker/ex-mayor), so as with the "Decatur Cutoff", the only time you'll hear "Fair Park Curve" is on traffic reports.
* "Ferguson Curve", as with the "Fair Park Curve", another S-curve on I-30 east of downtown, but shorter, and in the vicinity of the Ferguson Road exit. Also not an official name, only heard on traffic reports.
I really don't know where the traffic reporters came up with the names, other than maybe somebody decided years ago that the above terms would be good descriptive labeling conventions when referring to those spots on the radio.
Most all the other naming used when TV/radio traffic reports are on is a combo of actual numbered routes and/or freeway/tollroad/street names. Occasionally you'll hear TxDOT terms or construction project monikers like "DFW Connector" for the TX 114-TX 121 overlap between Grapevine and DFW Airport, or "the TEXpress lanes" for the tolled express lanes that are on I-635, I-35E north of I-635, I-35W between downtown Fort Worth and I-820, and I-820 on the north side east of I-35W.