ACI / AEI
ACI labels and AEI tags
ACI was a color-bar label the industry abandoned. AEI is the RFID tag that identifies the car to wayside readers.
ACI and AEI are two generations of trying to identify a car without someone reading the reporting mark by eye. They are not part of the weight block, and they are not placards.
ACI, Automatic Car Identification, was the color-bar label of the late 1960s and the 1970s. Trackside scanners were supposed to read the bars. Dirt, damage, and peeling labels made the system unreliable, and the industry dropped it. When you still see a faded color-bar panel on an old car, you are looking at a leftover, not at a system anyone is scanning.
AEI, Automatic Equipment Identification, replaced that idea with a passive radio tag. The tag is a small plaque on the side of the car. Wayside readers wake it up and record the equipment identity as the car passes. The tag does not replace the painted reporting mark. The mark is still the human-readable identification. The tag is for the railroad's readers.
A visible AEI tag tells you the car carries an electronic identity. It does not tell you the owner, the load, or where the car is going. Those come from the reporting mark, the other stencils, and from systems RailcarID does not have and does not republish.
Common questions
- What is the difference between ACI and AEI?
- ACI was a scanned color-bar label and was abandoned. AEI is a passive RFID tag read by wayside equipment. An old ACI label is a historical leftover.
- Does the AEI tag replace the reporting mark?
- No. The painted reporting mark is still how a person identifies the car. The tag is for electronic readers.