Thirty years ago railways in North America began searching for a system that would allow them to automatically identify rail cars. In the late 1960s the Association of American Railroads (AAR) adopted an optical identification system that used color coded labels. These labels were mounted on each side of the rail car. This system was called Automatic Car Identification or ACI. All rail car owners were required by the AAR to install these labels on their cars. This requirement lead to the full scale implementation of the ACI system in the early 1970s. Unfortunately, because dirt accumulated on the labels, and the labels began to deteriorate with age, the system's accuracy was much less than expected. ACI was eventually abandoned in the late 1970s. Because of this failure railways did not seriously search for another system to identify rail cars until 1986.
Burlington Northern was the first railway in North America to start the search again for an identification system. Burlington Northern had been closely following the efforts of various maritime shipping companies, such as American Presidents Lines, in their efforts to find a system to automatically identify containers. Based on the maritime companies' interest and their success with RF based identification systems, Burlington Northern began a testing program.
Burlington Northern initially asked nine vendors to present their identification systems. From this group of nine, Burlington Northern selected two systems for full scale testing. The two vendors selected were General Railway Systems (GRS) and Union Switch and Signal (US&S). The Union Switch and Signal identification system is manufactured by Amtech Corporation of Dallas, Texas.
In January, 1988, Burlington Northern equipped 1,500 taconite (iron ore pellets) rail cars in northern Minnesota each with a GRS and an Amtech transponder. Each vendor also installed three wayside reader sites. All tags were mounted on the sides of the rail cars.
In August, 1988, the Burlington Northern Railroad presented a paper on the results of their testing at the Association of American Railroads' Communication and Signal Annual Meeting. They reported that the accuracy of both systems over a six month period was in excess of 99.99%. Based on the spectacular results from both systems, the Burlington Northern asked the Association of American Railroads to form a committee to write an Automatic Equipment Identification (AEI) standard for the North American Rail Industry and suggested that the AAR use the current draft ISO standard for container identification as a starting point.
A committee was formed by the Association of American Railroads and charged with developing an Automatic Equipment Identification standard. Railways, such as Norfolk Southern, Union Pacific, CSX, and Canadian National, began their own testing programs and reported the results to the AAR's AEI committee.
The AAR, in August, 1989, informed various identification system vendors that Amtech's identification technology had been selected for the Automatic Equipment Identification standard.
By the fall of 1989, the AAR's AEI committee had selected a technology and defined the tag's data format. The only major decision that was still unresolved was the location of the tag on the rail car. This became a very controversial subject for the next nine months between two groups of thought. One group wanted to place tags on the sides of the rail cars and another wanted them underneath. Each location had its advantages and disadvantages in terms of cost and maintainability. The tags were tested and found to operate well in both locations. It was finally decided by the AEI Committee in the summer of 1990 that two tags would be mounted on each rail car, one on each side.
In July, 1990, the AAR Committee on Car Service sent a resolution to the O-T General Committee of the AAR to set a mandatory implementation date when all rail cars in interchange service would be tagged. The O-T General Committee is the highest operating committee within the AAR. The O-T General Committee requested that the AEI Committee perform a cost/benefit analysis on mandatory AEI implementation and recommend an implementation schedule. In October, 1990, the O-T General Committee approved the recommended AEI voluntary standard.
With these recommendations, in August, 1991, the O-T General Committee of the Association of American Railroads voted to make the AEI standard mandatory. The mandatory vote was ratified by the Association of American Railroads Board of Directors at their meeting in September, 1991. The mandatory period started on 1 March, 1992, and ended on 31 December, 1994. By the end of this period all 1.4 million rail cars in North American interchange service were to be tagged.
As of 31 December, 1994, Amtech had shipped over 3.1 million tags to railways in North America. The AAR reported that over 95% of the North American rail car fleeted was tagged. Over 3,000 readers have been installed by the railways in North America as of the end of 2000.