George,

The Orangeline busway is built over the ROW of the old Chatsworth branch, which ran from Burbank Jct, to Chatsworth, via Warner Center along the southern and western ends of the San Fernando Valley. The portion used for the busway runs from the North Hollywood Red Line station (and the recently restored SP/PE NOHO station), west to Warner Center, and then North to the Chatsworth ML station parallel to Topanga Canyon Blvd..

You are probably thinking of the PE line which went north on north Van Nuys from where the SP branch and PE kind of paralleled each other, in the east Valley from North Hollywood, it went north on Van Nuys Blvd, west across to Sepulveda, and then north again, and then back east again, over to San Fernando, via Brand (in the north Valley). That final segment was the last "stranded" electrified PE freight segment in the Valley, which connected to the SP at San Fernando. That "wide median" is a potential "future" route, of some kind, and is now being looked at for early implementation of rapid bus service.