MNR does not currently assign train numbers that fall into Amtrak’s numbering scheme, but in a pinch, it could happen. In operations, Amtrak trains identify themselves on the radio as “Amtrak xxx.” In MNR’s various IT systems, Amtrak train numbers carry an “A” prefix.
Freight trains don’t have numbers, per se; they have alphanumeric symbols.
Most commuter railroads with which I’m familiar have a very specific numbering scheme for their trains. Generally, the number identifies the line/branch on which the train operates, and even which outlying terminal the train runs to/from. On MNR, weekday numbering is as follows:
100-299 - not used
300-399 - Lower Harlem, generally that short-turn somewhere south of NWP, although when the 500-series was exhausted, some NWP trains got 300-series numbers
400-499 - Lower Hudson, generally that short-turn somewhere south of Harmon
500-599 - Lower Harlem, originating/terminating in NWP
600-699 - Upper Harlem, as far north as Southeast
700-799 - Lower Hudson, originating/terminating in Harmon
800-899 - Upper Hudson
900-999 - Upper Harlem, originating/terminating north of Southeast
1000-1199 - New Haven Line deadheads
1200-1299 - Inner New Haven short turns
1300-1399 - Inner NH, originating/terminating at Stamford
1400-1499 - Outer NH short turns (and Bridgeport Yard trains)
1500-1599 - Outer New Haven, originating/terminating at New Haven
1600-1699 - not currently used
1700-1799 - New Canaan Branch
1800-1899 - Danbury Branch
1900-1999 - Waterbury Branch
2000-2999 - Hudson and Harlem deadheads
3xxx and 4xxx numbers are either pre-holiday getaways, combo trains to support those getaway trains, or special trains that Aren’t anticipated to operate forever.
Generally, on weekends, prefix Hudsons with “8” (8xxx), Harlems with a “9” (9xxx), and on the New Haven replace the leading “1” with a “6”.
There are exceptions and variations to this, but this is the general rule.
Palm Beach County, FL