The Amtrak train schedules on the Amtrak site, and the published system timetables, include that information.
As an aid in reading the Amtrak schedules, if you look at trains 92 and 98, which depart Miami northbound, you will notice an " R " next to the times listed for each of the stations up to and including West Palm Beach for those trains. That " R " means those train will only allow passengers to BOARD the train at those stations, nobody is allowed to get off the train at those stations on those trains. On trains 91 and 97, which run southbound to Miami, you will notice a " D " next to their times at the stations from West Palm Beach on south to Miami. That " D " means that the trains only allow passengers to get off those trains at those stations - no passengers are allowed to board 91 or 97 at those stations. Also, where those " D " symbols appear, the train will not even stop at a " D " station if there are no passengers on board for whom that station is their destination, and they will depart those stations as soon as their station work is done - they do NOT have to wait for the scheduled time before they depart those stations. Frequently those trains can enter those corridors behind schedule and yet arrive at the final destination for the train on time or even early because they can make up significant time in that corridor, depending on passenger load and whether some stations can be bypassed completely.
There are some other stations in the system that operate this way as well, and those " R " and " D " letters signify that for those trains at those stations. For instance, the Long Distance trains including 19/20, 89/90, 91/92, 97/98 have the same sort of restrictions in roughly the Washington D.C. - New York corridor. Southbound they will take on passengers ONLY, and not allow passengers to get off at those stations, and Northbound they only allow passengers to get off the train, nobody can board at those stations.
Just as Tri-Rail provides frequent service from West Palm Beach on to down south of Miami, and therefore Amtrak does not allow "commuting" passengers on the Amtrak trains in that corridor, Amtrak and others provide frequent commuter and regional service in the Northeast Corridor from Washington on northward, so they don't allow the Amtrak long-distance trains to carry those type of passengers.
Also, Tri-Rail stops at quite a few MORE stations in the West Palm to south of Miami corridor than Amtrak does. Tri-Rail stops at every station Amtrak does EXCEPT the Amtrak Miami station itself, if I recall correctly, but Amtrak does NOT stop at all the Tri-Rail stations. Tri-Rail has a pretty good web site, and the trains themselves provide excellent service in that corridor - I live in the Orlando area, but have taken Amtrak down to that area several times and then used Tri-Rail and the other Southeast Florida mass transit systems, and those systems work pretty darn well and seem well-coordinated and integrated with each other.
Of course, they very rarely (i.e., NEVER) have to deal with winter snows that muck up the travel system up north. :lol:
One of the keys to understanding how the train schedules actually work is ALWAYS to look for symbols like the " R " and " D " and others, and when you see something like that, look up in the explanation of symbols on the schedule or timetable to see what they mean.