From about 1992 until around 2004 or so, the Metrolink San Gabriel Subdivision (between Los Angeles and San Bernardino) had a diverging route as the "main through route" at CP Cambridge.

The line west of this point was original Southern Pacific (ex-PE) Baldwin Park Branch and east was the Santa Fe 2nd District or Pasadena Subdivision. All westbound Metrolink trains would take a diverging route at CP Cambridge just after leaving the Claremont Station. The straight or "normal" route thru the switch kept you on the old Pasadena Subdivision and was used by the ATSF and later BNSF local freights plus the occasional Metrolink special movement. THe Metrolink Employee Timetable even had a Special Instruction just for this location.

Around 2004, the section of track was doubled tracked, the San Gabriel Subdivision was realigned to signifantly reduce the curvature and the switch was made so straight or "normal" movement thru the switch kept you on the main line.