On the existing cars train length is input by the operator. If a 10 car train was set in the three car position, the train would stop near the center of the platform, leaving several cars at the rear of the train short of the platform. The automatic train control equipment would recognize that there were cars not at the platform and prevent all the doors from opening. Most of this is in the ATC equipment, which is not new to BART. There may have been an attempt to get the train to count its own cars on the new equipment. If this did not work and left cars short of the platform, none of the doors on the train would open automatically. Each pair of doors can be opened manually at each doorway regardless of weather it was at a platform or not.