Well Tri-Rail generally runs six sets, although it can get to be up to seven sets at times. There are five "standard sets" which during the bulk of the year (non-summer) are an F-40 on the south end, two standard coaches, and a cab car on the north end. Then there are two "special sets." There is what I call the SOFTA (School of the Arts) set, which makes two round trips per day hauling kids to and from the School of the Arts in West Palm Beach to their home communities in Northern Broward and all of Palm Beach. This set usually gets 810/811 as it's F-40 and then five standard coaches and a cab car (511). The SOFTA set makes its weekday runs as P604, P609, P616, and P619. The last "special set" is the Emergency set. This set spends most of its time in the West Palm Yard held in reserve service in case of set failure or major delays. This set consists of an F-40, a standard coach, and one of the UTDC cab cars. Now as far as cab cars go, Tri-Rail owns six UTDC cab cars (501-506) and five Bombardier Cab Cars (507-511). 511 works as the SOFTA Cab Car, the other four work standard sets. As for the UTDC cab cars 504 works as the only one leading a standard set, while 501 works the Emergency set. As for the others they are placed in the middle of trainsets as a "standard" coach. The 502 will show up on Tri-Rail's website as the tracking unit for the 504 (504-506 have no GPS unit installed). So there you have it, everything you wanted to know about the Tri-Rail sets.