That "ACI" system on BART died almost thirty years ago - never was very good. It was replaced by clerical help. BART had the same problems with it that the railroads, post office, and many trucking outfits did. It simply had only a 95 to 97 percent accuracy rate, even with the daily car washing that BART once did.

Even an error rate of less than one percent would still force the requirement for human consist verification, thus continued human employment. ACI failed to save the railroads or anyone else, a thin dime; actually adding its cost to that of the clerical help it failed to replace. Thus interchange requirements for the ACI labels were unceremoniously dumped years ago - I forget exactly when. The hardware quickly became obsolete and impossible to maintain - no parts availability.

Radio-transponder tag technology is very accurate, and is used in hundreds of applications besides transportion (shop-lifting detection and automatic toll collecting for example), and is thus relatively cheap. Coupled with improved car location software, it did succeed in eliminating the need for consist verification - car clerks.

Of course, we all know that those clerks served other useful functions than just car tracking. But alas; those uses were too subtle for most railroad managers and bean counters to understand. Thus the railroads still suffer anyhow - just in a different way.

OPB