This module was built in 2002 to allow a double track run into a peninsula and back.
In 2004 we added a connection for the yellow line to bypass the peninsula.
In 2005 another connection was inserted to allow operation as a nearly-regular N-TRAK junction module. (The red line does not keep the loop closed.) It was used as a junction the same summer in San Antonio.
After two “classic” junctions were built, and with persistent wiring problems in the junction layout, in 2009 the extra connection from blue to alt-blue on the spine end was removed again, thus leaving the blue line from the spine ending up exclusively in the yellow line of the underlying corner module structure.