In spring 2005, the current CBTC-enabled R143-class equipment was expected to run under full automation with a single operator (known as OPTO, or One Person Train Operation) acting as an attendant to monitor the train's operation and take over manual operation if necessary. However, technical mishaps including the test train rolling away by itself delayed the start of automatic train operation. The project caused numerous service disruptions on the L at night and on weekends. Frequently, service was shut down in separate sections of the line, usually from Eighth Avenue to Lorimer Street, Lorimer to Broadway Junction, or Broadway Junction to Rockaway Parkway. During this time, shuttle buses served suspended areas. This project also required the temporary closing of some stations, either in one direction or both directions, and for the line to be operated in two sections.