Intermodal Equipment Glossary

For general Intermodal terms, see the Intermodal Glossary



Agent Railroad
A railroad moving a container or providing terminal services as an agent for an EMP participating railroad. Containers in the care or custody of an agent railroad are treated as though they are in the care and custody of an EMP participating railroad.

Assigned units
IMC's can acquire an assignment of units. The purpose of taking units under assignment is so that the units will not be returned empty to the ramp and will constantly be re-loaded and shipped in a high volume lane on the rail. In return, the customer typically receives a lower per diem rate.


Bad Ordered
A unit that is loaded improperly, mechanically defective, or has safety violations is considered "bad ordered."

Bill Of Lading
A document issued by an IMC to the railroad specifying shipment instructions. Bill of Lading is commonly referred to as "EDI 404," "shipping instructions" or "billing."

Billable Time
Any time that a unit is not under control by a railroad and is under a particular IMC's control.

Billing Cycle
A biweekly process of invoicing by REZ-1, which is run as follows: Reservations that complete between the 1st and 15th of each month are invoiced around the 17th of the month. Reservations that are complete between the 16th and the end of the month are invoiced around the 3rd of the following month.

Billing Dispute
A discrepancy, submitted by fax or electronically filed via REZ-1, with any portion of a statement.

Booking/Reservation Number
A three part series of characters given out by REZ-1 to an IMC who, in turn, will give it to a drayage provider so that they can use it at a ramp to pick up an empty unit for loading and shipment.

  • The first four characters indicate the units program and size (ex. EU48. E means EMP. U means standard. 48 means 48 feet long.).
  • The next character is the reservation type (ex. G means general).
  • The last 5 characters are a series of randomly chosen numbers (ex. 34772).

After a reservation's shipment has been delivered and the reservation has moved into billing by REZ-1, the booking/reservation number can be "recycled" and applied to some future reservation.

Bundled Product/Rate
Term used to describe an intermodal product for which an allotment of "free days" or relief of per diem is built into the line haul rate. SPDU containers are marketed as a bundled product.


A rubber-tired under-frame on which a container is mounted for street or highway transport.

Car Location Message, a railroad generated message that reports the location of moving rail cars, including flatbeds carrying intermodal units.

A large, reusable receptacle that resembles a truck trailer without wheels (chassis), that is lifted on to flatcars. Containers are designed for all modes of intermodal transport, and can accommodate smaller cartons or cases in a single shipment, designed for efficient handling of cargo.

Crossover Charge
Crossover charges occur when a unit is taken from one ramp and returned to a different railroad in the same, or a different metro area. In specific cities, the railroads may impose crossover charges.

When a unit is moving from one railroad to another, at the point of exchange, it will be trucked from the first railroad's yard, to the second railroad's yard. This time on the road is called "cross-town."



Compensation paid for the use of a container during loading or unloading.

Destination Dwell
Demurrage time after a unit has reached its destination by railroad.

Destination Ramp
The railroad terminal that a unit will go to, to be picked up by truck for delivery.

The process of electronically collecting funds from an IMC's bank account by REZ-1 via the Automatic Clearing House (ACH) process.

Drayage Provider
A trucking company.

Term used that refers to a trucking company or an individual trucker.

Drop Charges
The railroads may impose drop charges at certain ramps to units that return to the ramp empty. Drop charges are used to prevent congestion.

Same as demurrage; used more in rail industry communications than in legal contracts.


Electronic Data Interchange, the protocol used by companies to send and receive electronic messages concerning container reservations, movements, and invoices.

A domestic interline container service offered by Union Pacific and Norfolk Southern. Also included in the program are agent railroads, such as I&M Rail Link, Iowa Interstate, Wisconsin Central and Kansas City Southern. EMP provides a fleet of nearly 35,000 53' domestic containers and chassis that move throughout a nationwide intermodal network.


A freight car having a floor without any housing or body above. Frequently used to carry containers and/or trailers or oversized/odd-shaped commodities.

Freerunning Unit
A unit that is not assigned and can be used by any IMC.

Free Time
The period allowed the owner to accept delivery before storage or detention charges begin to accrue.



General Move
A shipment in which the railroad receives revenue for its services.

Units can have different grade types, such as "food grade," "paper grade," "general grade," etc. All EMP units are general grade.


High Cube
EMHU's are also called "high cubes." They are 53-feet in length like the EMRUs, but are greater in height, thus allowing greater cubic capacity.


Intermodal Marketing Company. This company is a broker or "middleman" who reserves containers (through REZ-1) for their customers, who are in turn, companies that want to ship truckloads of their goods from manufacturing plants to wholesalers, or from wholesalers to retailers.

Term applied to units arriving at a railroad terminal over the road, from a trucking company.

Ingate Load or Load/Load
Term applied to a unit re-loaded while away from the railroad. A trucker takes the loaded unit from a railroad terminal and unloads its cargo, then loads the same unit with a new shipment and returns the unit to the terminal for further hauling by the railroad.

Interchange of equipment between differing modes of transportation, which include: rail, truck, or ocean.

The written recap of an IMC's reservation from REZ-1, to include, but not limited to, cancellation, expiration, origin and destination dwell times.


A report filled out during the ingate and outgate process. The J-1 details damage to the unit, container information, shipping information, drayman involved and time of ingate/outgate.


The pre-described course a unit follows from origin to destination on the railroad, also known as a valid origin/destination pair. Valid "lanes" are determined by participating railroads.

Lane Incentive
A lane incentive is applied when a unit ships as a load from a specific origin ramp to a specific destination ramp. (Other restrictions may apply.)

Line Haul
The movement of a unit on the railroad from origin to destination.

Line Haul Rate
The amount charged by the railroad (to an IMC) for a shipment, dependent on the actual origin and destination.



Metro Code
A code assigned to a particular region indicating its location in or near a large city. All EMP ramps have an assigned metro code. Several of them may be included in the same metro code.

Misuse Charge
A misuse charge is a penalty imposed by the railroads for taking a unit out of one metro area and returning the unit to another metro area empty or loaded. For example, if a unit outgates in Detroit and ingates empty or loaded to Chicago, a misuse charge will occur. These charges are determined by participating railroads and can be changed at any time.


The process whereby the railroad will inform the drayage provider or IMC that a unit is available for pickup. The notify will place the move in a destination dwell status.


A unit is considered off-route when it travels in an invalid lane (such as Las Vegas to Allentown) or when it travels on a non-participatory railroad (such as BNSF Railway). An IMC will be charged off-route charges by REZ-1 until that unit is brought back to a valid terminal.

Origin Dwell
The demurrage time before a unit is brought to a railroad terminal to be shipped.

Origin Incentive
Origin incentives apply when units are returned to the specified origin ramp as a load for shipment. (Other restrictions may apply.)

Origin Ramp
The railroad terminal that a unit is brought to after being loaded for shipment.

Defines the event of a unit being taken from a railroad terminal by a trucking company.

OutReach Program
A rail-truck or truck-rail movement in which Union Pacific has combined the rail and drayage into a single transportation package for EMP and SPDU containers. Containers are shipped via rail from one terminal to another. After that, a contracted drayage firm drays the container to the paper ramp operators lot for customer pickup. The process also works in reverse as well, shipment can originate with the truck movement and then move to the rail portion of the movement. Also referred to as a paper ramp.



Paper Ramp

A rail-truck or truck-rail movement in which a participating railroad has combined the rail and truck movements into a single transportation package for EMP units. Units are shipped via rail from one terminal to another. After that, a contracted drayage provider trucks the unit to the paper ramp operator's lot for customer pickup. The process also works reverse as well. A shipment can originate with the truck movement and then move to the rail portion of the movement.

Pick-Up Incentive
Pick-up incentives credit customers when a unit is picked up empty from the specified reservation ramp(s).


Rail User Number
An ID number given to an IMC by REZ-1. An IMC will use this number when they make reservations to prove that they are a valid member of the EMP reservation program.

Slang word for an intermodal terminal. Ramps were originally structures, permanent or temporary, from which trailers or machinery are driven onto or off of a railroad flatcar.

A shipment generated by the railroad for repositioning empty units from one location, to another location in which they can be better utilized or to a location that is deficient.

Reservation Ramp
Term used by REZ-1 to describe a railroad terminal, where an empty unit is picked up with a valid booking/reservation number.

Return Ramp
A railroad terminal that a unit is brought back to after dropping off its shipment. This drop off will complete the original move. It will also start a new move if it's brought back with another shipment.

Company that manages the containers/trailers in the EMP program and controls the reservations made against them.

"Road Worthy" Unit
Any unit that is not bad ordered.



Standard Carrier Alpha Code, used for identifying truckers, railroads and other conveyors.

Shared Incentive
A shared incentive occurs when two railroads join together to share in the cost of a lane incentive.

Standard Point Location Code, used by railroads to identify their ramps (terminals) and other (intermediate) locations.

Street Interchange
A street interchange transfers financial responsibility of a unit from one IMC to another on a date and time that is specified by the drayage firm in control of that container or by an IMC that has financial responsibility for that particular container.


See Ramp.

A unit that has its own rear wheels, and therefore cannot be stacked on one another.

The time that a unit is on the railroad. Transit starts from the ingate load at origin and goes until the notify at destination. Transit calculates the amount of time a railroad was in possession of a unit and how long it took to ship that unit from point A to point B.


UMAX is a domestic interline container service offered by Union Pacific and CSX Intermodal. UMAX provides access to a fleet of more than 35,000, 53-foot domestic containers and demonstrates both carriers' commitment to maximize customers' shipping options, while featuring truck-competitive services.

Unbundled Product/Rate
Term used to describe an Intermodal product for which the line haul does not include any free time and the per diem is billed separately. EMP is marketed as an unbundled product.


A document giving details and instructions relating to a shipment of goods. A waybill is issued by the railroad after receipt of the Bill Of Lading.