The classification system is one of the few pieces of rail jargon that is genuinely simple, and it still trips up experienced shippers — mostly because the word "class" sounds like it should describe how a railroad operates. It does not. A Class I carrier is not a carrier that runs long trains fast; it is a carrier that books more than a billion dollars a year. Everything shippers actually care about — reach, responsiveness, pricing authority, whether anybody answers the phone — correlates with the class only loosely. Knowing where the lines are drawn, and what they do and do not predict, saves you from a set of assumptions that cost real money.
The Classification System in One Table
Railroads are classified by annual operating revenue and nothing else. The Surface Transportation Board sets the thresholds, publishes an inflation deflator each June based on producer price index data for line-haul railroads, and restates the dollar figures accordingly. Track miles, locomotive count, train frequency, service quality, and geography have no bearing on the tier a carrier lands in.
| Class | Annual operating revenue (2025 reporting year) | How many | Typical profile |
|---|---|---|---|
| Class I | Above $1,053,709,560 | 6 freight carriers | Continental mainline networks, thousands of route miles |
| Class II (regional) | $47,299,851 to $1,053,709,560 | Fewer than two dozen | Hundreds of route miles, real line-haul service between markets |
| Class III (short line) | Below $47,299,851 | Roughly 600 with Class II carriers included | A branch or cluster of branches, one or two interchanges |
The base figures behind those numbers matter if you are reading older material and wondering why the thresholds jumped. In 2021 the Board reset the Class I line from $250 million in 1991 dollars to $900 million in 2019 dollars, and converted the Class II floor from $20 million in 1991 dollars to $40.4 million in 2019 dollars, effective for reporting years beginning January 2020. Every figure published since is that base run forward through the deflator. Sources written before the reset quote numbers roughly a quarter the size, which is why you will find "$250 million" and "$1.05 billion" both presented as the Class I threshold on the open web.
One consequence worth internalizing: a railroad's class can change without a single mile of track changing hands. A regional carrier that lands a large unit-train contract can cross into Class II from Class III, and back out of it when the contract ends. The classification is an accounting outcome, not an operating identity.
Class I Railroads by Size
Six Class I freight railroads operate in the United States: BNSF Railway, Union Pacific, CSX Transportation, Norfolk Southern, Canadian National, and Canadian Pacific Kansas City. Ranked by route miles, BNSF and Union Pacific lead at roughly 32,000 miles each across the western two-thirds of the country, with CPKC, CSX, and Norfolk Southern clustered in the 19,000 to 20,000 mile range and Canadian National close behind on its North American network.
Those rankings move around depending on the yardstick. Measure by revenue and Union Pacific usually tops the list; measure by carloads and the order shifts again; measure by ton-miles and the western carriers pull ahead on length of haul. For a shipper the ranking is close to useless information. What matters is which of the six physically reaches your origin and which reaches your destination, because that determines whether you have a single-line move, an interchange, or a captive lane with no competitive alternative.
A seventh name enters some counts: Amtrak clears the revenue threshold and is technically classified Class I, but it hauls no commercial freight, so shipper-facing lists leave it out. Our full breakdown of the six carriers, their territories, and the pending merger that could take the count to five is in Class I railroads explained.
Class II: The Regional Tier Nobody Explains
Class II carriers are the middle tier, and the one most shippers have never thought about. Fewer than two dozen railroads sit in it, typically operating several hundred route miles with enough network to run genuine line-haul service between markets rather than just feeding an interchange. Carriers in this range include Wheeling & Lake Erie (roughly 840 route miles), Wisconsin & Southern (roughly 750), Rapid City, Pierre & Eastern (roughly 680), Buffalo & Pittsburgh (roughly 660), Iowa Interstate (roughly 580), and Florida East Coast (roughly 350).
Note how loosely revenue tracks size in that list. A 350-mile carrier and an 840-mile carrier occupy the same tier, and some Class III short lines out-mile some Class II regionals. Montana Rail Link ran 900-plus miles of heavy mainline for decades without clearing the Class I bar. If you want a size-based view of the industry rather than a revenue-based one, the Association of American Railroads and the American Short Line and Regional Railroad Association maintain their own operating categories — regional, local line-haul, switching and terminal — that use a mileage criterion of about 350 miles alongside revenue. Those categories describe how a railroad works. The STB classes describe what it earns. Both are in circulation, and conflating them is where most of the confusion in this topic comes from.
What a Class II carrier means for your freight
A regional has more operating muscle than a short line: multiple crews, its own dispatching, sometimes several interchange points with different Class I carriers. That last part is the commercially interesting one. A short line with a single interchange hands you exactly one long-haul option. A regional touching two or three Class I connections can route your car through whichever gateway prices best, which is leverage you can actually use in a negotiation.
Regionals are also large enough to hold real contract authority and small enough that a mid-size shipper is a meaningful customer. If you move 200 cars a year, you are a rounding error to a Class I commercial team and a named account to a regional. That asymmetry is the single best argument for checking whether a Class II serves any part of your lane before you assume the move has to go direct.
Class III: Short Lines, Switching, and Terminal Roads
Class III is everything below $47,299,851 in annual revenue, and it is where the vast majority of American railroads live. Combined with the Class II regionals, roughly 600 short line and regional railroads operate in the United States on close to a third of the national freight rail mileage, and about one in five cars moving on the network touches one of them.
The tier holds three distinguishable business models:
- Short lines — a branch or cluster of branches, usually spun off from a Class I in the 1980s or later, hauling cars between local industries and an interchange.
- Switching railroads — no meaningful line haul at all; they move cars around an industrial district or between the yards of connecting carriers.
- Terminal railroads — port, plant, or belt operations that exist to serve a specific facility or gateway, often jointly owned by the carriers that use them.
Practically, Class III status tells you the railroad is small: a lean staff, a short chain of command, and revenue concentrated in a handful of customers. That has real upside. You can usually reach a decision-maker on the first call, and a short line that wants your business will build track, adjust a spot schedule, or work a car placement problem in ways a Class I never will. The downside is that the short line often cannot control the number you care about, because the through rate is set by the connecting Class I and the division between carriers is negotiated railroad-to-railroad. Our guide to what a short line railroad is covers the working relationship in depth.
Why "Class A Railroad" Returns Nothing Useful
There is no Class A railroad in the U.S. freight rail system. The Surface Transportation Board uses Roman numerals — Class I, Class II, Class III — and no letter-based tier has ever existed for carrier classification. If you searched the term and got a mess of unrelated results, one of three things is usually going on.
You mean Class I. "Class 1 railway" and "Class A railroad" are typed by people looking for the same six companies. The Roman numeral gets read as a letter often enough that the two queries have merged.
You mean FRA track classes. These are real, numbered rather than lettered, and describe the physical condition of the track and the maximum speed permitted on it — not the size of the company that owns it. A Class I railroad can and does own Class 1 track on lightly used branches.
| FRA track class | Maximum freight speed |
|---|---|
| Excepted track | 10 mph (no loaded hazmat placarded cars) |
| Class 1 | 10 mph |
| Class 2 | 25 mph |
| Class 3 | 40 mph |
| Class 4 | 60 mph |
| Class 5 | 80 mph |
This distinction has money attached to it. A short line operating Class 2 track at 25 mph moves your car slower than the mainline behind it, and that shows up in cycle time on captive equipment. When a carrier tells you a branch is "excepted," it is telling you something specific and consequential about what it can legally handle.
You mean something else entirely. "Class A" shows up in railroad common stock designations, in AAR mechanical designations for equipment, and in track-class conversations outside the United States. None of them describe a carrier tier. If someone in a freight conversation says "Class A railroad," ask which they mean before you nod — nine times out of ten they mean a Class I.
What the Class Tells You — and What It Doesn't
Once you know a carrier's class, you can reasonably infer four things.
- Reach. Class I means the carrier can line-haul your freight across a continent under its own network. Class II means it can move freight meaningfully between markets. Class III means it is a first-mile or last-mile operation in almost all cases.
- Pricing autonomy. A Class I publishes the through rate for a move that crosses several railroads and divides the revenue behind the scenes. Smaller carriers frequently quote only their own segment, either as a division of a through rate or independently under a Rule 11 split-rate arrangement.
- Access to your account. Class I commercial teams are built around large repeating volumes. Below that, you get more attention per carload.
- Data availability. Class I carriers publish detailed cost and service metrics. Below that tier, the information is thin, and estimating a lane requires piecing together tariffs, interchange behavior, and known division practices.
What the class does not tell you is more important. It does not predict service quality — some short lines run circles around Class I locals, and some do not have enough crews to spot cars twice a week. It does not predict whether your rate will be competitive; a captive Class I lane can price worse than a routing through two smaller carriers with a competitive gateway. It does not predict equipment availability, which follows the car supply for your commodity rather than the carrier tier. And it does not predict how hard the carrier will work a problem when a car goes missing or arrives damaged.
The practical takeaway: use the class to understand the structure of your routing, then evaluate each carrier on its own record. If you are building that evaluation from scratch, our guide on how to choose a rail freight logistics partner lays out the criteria that actually correlate with outcomes.
How the Three Tiers Show Up on One Shipment
The classification system stops being abstract the moment you trace a real car. Take a covered hopper of distillers grains moving from a plant on a short line to a feed mill served by a different railroad several states away.
- Class III first mile. The short line spots the empty at your plant, you load it, and the crew pulls it on its next scheduled run — often two or three days a week, not daily. The short line hauls it 30 miles to an interchange yard.
- Interchange. The car is delivered to the Class I, inspected, and placed in the connecting carrier's train. This is where cars sit if the paperwork is wrong or the receiving carrier's yard is congested. Our railroad interchange guide covers what actually happens here and where the delays come from.
- Class I line haul. The long segment, typically through one or more classification yards, where the car is sorted onto successive trains headed toward the destination region.
- Delivering carrier. A Class II regional or another short line takes the car from the final interchange and places it at the mill. If the destination is on a second Class I, the move crosses a carrier boundary again.
Three or four railroads, three different classes, one bill of lading, and usually one rate. The class of each participant tells you where the control points are: the Class I sets the rate and owns the schedule risk on the long segment, and the small carriers on either end own the spot timing that determines whether you pay demurrage. When a move goes sideways, knowing which tier owns which segment is how you figure out who to call.
Rail is a longer-cycle mode than truck by a wide margin — weeks rather than days on a cross-country move, with variability at every interchange — and the multi-carrier structure described above is exactly why. That is not a reason to avoid rail. It is a reason to plan inventory around it and to understand the handoffs before your first car moves.
Working out which carriers touch a specific lane, what each tier controls, and where you have competitive options is lane-by-lane analysis. It is the core of what a rail logistics provider does day to day. If you would rather build the capability internally, our free rail logistics course works through carrier structure, network design, and pricing across ten modules, and the rail freight glossary is worth keeping open the first few times you talk to a carrier.
Frequently Asked Questions
What are the three classes of railroads?
Class I, Class II, and Class III. The Surface Transportation Board defines all three by annual operating revenue and re-indexes the thresholds for inflation every year. For the 2025 reporting year, a Class I earns more than $1,053,709,560, a Class II falls between $47,299,851 and that figure, and a Class III earns less than $47,299,851. Six freight Class I carriers operate in the United States, fewer than two dozen sit in Class II, and everything else is Class III.
What is a Class A railroad?
There is no Class A railroad in the U.S. freight rail system. The Surface Transportation Board uses Roman numerals: Class I, Class II, and Class III. Searches for "Class A railroad" usually mean Class I, and occasionally they are aimed at FRA track classes, which are numbered 1 through 5 and describe maximum allowable speed rather than the size of the company.
How do Class 1 railroads rank by size?
By route miles, BNSF Railway and Union Pacific are the two largest at roughly 32,000 miles each, followed by CPKC, CSX, and Norfolk Southern in the 19,000 to 20,000 mile range, with Canadian National close behind on its North American network. The ranking shifts depending on whether you measure route miles, revenue, carloads, or ton-miles. None of it changes which carrier serves your facility, which is purely a question of geography.
What is a Class 3 railroad?
A Class III railroad is any carrier with annual operating revenue below the indexed threshold, currently $47,299,851. The tier holds almost every short line, switching, and terminal railroad in the country. Class III carriers typically operate one branch or a small cluster of branches, connect to the national network at one or two interchanges, and handle the first or last miles of a move that a larger railroad line-hauls.
Does a railroad's class affect my freight rate?
Not directly, but it shapes how the rate is built. Class I carriers publish through rates and divide the revenue with connecting carriers behind the scenes, so you often see one number for a move that involves three railroads. Class II and Class III carriers may quote their portion separately under a Rule 11 arrangement. The class tells you how much pricing autonomy a carrier has, not what the number will be.