Travelers' Information Stations (TIS), also called Highway Advisory Radio (HAR), are licensed low-powered non-commercial radio stations, used to broadcast information to the general public, including for motorists regarding travel, destinations of interest, and situations of imminent danger and emergencies. These are extremely interesting targets for DXers but very rare in the headphones, and because of the huge number of those stations in USA (over 2,300), they tend to fill TURTLE/NA MAP/LOCATOR/etc. in vain most of the time. This is why JAGUAR has moved these stations to a separate TIS database, available only on demand.
The TIS database is created automatically from each monthly TURTLE database and saved in the TURTLE folder with a name format of TURTLE-YYYY-MM-TIS.txt. The TIS databases cannot be opened with the standard "LOAD FROM DISK" function.
You can open the USA TIS database from DATABASE BAR: click the SLIDER button so that you will see the standard TURTLE window and DATABASE BAR. Normally, you will see your current TURTLE version (TURTLE-YYYY-MM) in the middle of the bar. Move the mouse over that area and the TURTLE and MORE buttons can be seen. Click the MORE button and select USA TIS from the popup menu
You can also press ALT-T repeatedly to rotate TURTLE > USA TIS > CATBOOK > KOJE > TOMCAT.