This is from a recent email from the FAA Safety Team:
The FAA will soon begin limited use of a Temporary Restricted Area (TRA) in certain areas when the types of operation(s) to be conducted there require a TRA. The flight rules that apply to a TRA are the same as a Restricted Area (RA). The best FAA resources to view any TRAs upcoming or active are the FAA Special Use Airspace (SUA) website and the Notices to Airmen Publication (NTAP).
Usually when the FAA wants to temporarily restrict access to airspace it puts up a TFR and it isn't clear from the wording of the email what a TRA is, why the FAA would create one rather than a TFR, and what the operational differences are between a TRA and TFR.
What is a TRA and how does it differ from a TFR?