This page of text describes safe places to railfan Tuscaloosa from.
Note: Tuscaloosa has numbered STREETS and numbered AVENUES. Keep them straight or get lost.
See this page for maps of Tuscaloosa.
Tuscaloosa is currently served by two major railroads, plus Amtrak. Norfolk Southern runs 25 to 35 trains a day through the city, Kansas City Southern runs about 6 to 10 per day. The Amtrak runs on NS tracks, going north through town at about 12:30 pm daily, and south at about 2:00 pm.
There are many great places in the city to see trains, including places where you can park and wait between KCS and NS mainlines (about 150 feet appart). Also, NS's yard is easily observed without tresspassing on two sides. KCS's yard, while much bigger, is harder to view without tresspassing.
The NS and KCS lines are withing 150 feet of each other at the 4th Ave crossing, Hackberry Lane, 10th Ave crossing, and 12th Ave crossing. Between Hackberry and 10th there are some decent sight lines where you could stand on either side and get photos of both tracks (KCS and NS trains happen to be going by at the same time more often than you might expect).
Suggested spots for safe viewing of the KCS yard include T.Y. Rogers, JR Ave/27th Ave (it goes by both names) or the 9th street overpass (best yard view, but you'll want a telephoto lens or binoculars for a close up view of most of the yard). KCS's Tuscaloosa offices are along T.Y. Rogers, JR. Ave. Another good viewing location is the 15th street overpass (sidewalk), this crosses above T.Y.R.Jr.Ave. and the main line. The neighborhood surrounding the KCS yard is a safe place durring the day (the county jail is right next to the yard) but it's best to stay in the car at night--this is advice from KCS employees and personal experience.
The NS/Amtrak station is also a good, safe place to watch trains. Train crews are occationally talkative while waiting in/near the Crew Room. The Amtrak employee is friendly some days, and "busy" (my words, not his) on other days. The station is located at the intersection of Greensboro Ave and Hargrove/20th Street (has two names, but in the area of the station is more commonly called Hargrove), also near 18th and 16th Avenues. The NS yard is next to the Amtrak station.
Another unique viewing location in Tuscaloosa is the Interlock. KCS employees still regularly call it the "Southern Crossing" and NS's main line has a sign a mile away that reads "Railroad crossing 1 mile". The Interlock is another place that can be visited in the day, but should be avioded at night. This small section of land is actually surrounded by, but not within, the city limits. From the station, go across the tracks on Greensboro Ave to 35 Street (about 3 minutes). Turn right onto 35th, you will cross over I-359 and the KCS tracks. Immediately after crossing the Norfolk Southern tracks (at grade), turn right onto 26th Ave. This is a small road between Tamko Roofing Products and the NS main (and is a safe place to park and watch NS trains). Continue on 26th, across Tamko's tracks; the road sharply curves right and immediately there is a left turn--take it--this is still 26th Ave and you should still be parallel to the NS main. Follow this road (it gets curvy and narrow) until you see a tower and have to cross tracks... those tracks are KCS tracks, NS is right behind the tower. KCS only switches this area about once a day and NS trains get priority. KCS owns the tower and wants vaguely to get rid of it (but they don't want to spend money on it). The tower is unlocked, but full of trash (clean enough to go in and look arround at). The second floor is not accessable (and the only thing up there are weeds and birds).
At the far end of Greensboro Ave (near 4th Street) is the L&N train station. The old L&N line has since been removed, but the station still stands. The area of 4th Street and 23rd Ave was once street-run by the trolley company; many of the warehouses have been converted to bars and restruants--this is a very safe and nice place to pick up something to eat and drink after a day of railfanning.
There are a lot more cool places in Tuscaloosa to watch trains, get good photos, and be safe... too many to name.
Just out of Tuscaloosa (vaguely out of it) is Holt. Holt is served by KCS and has a steel mill; the mill has a switcher and at least two trackmobiles, but the switcher is really hard to get a good photo of... good luck and stay out of Holt at night.