Uploaded September 2026 | Updated September 2026, 3 weeks ago
Caltrain's short signal blocks makes it somewhat easier to observe signal progressions as trains move down the line. Here we see the southbound milepost 25.4 automatic and CP-DUMBARTON absolute signals just south of the Redwood City platform. As the southbound train advances we see the Milepost 25.4 signal change to Advance Approach and as the CP-DUMBARTON changes from Approach to Advance Approach, the 25.4 signal changes to clear.
If you are wondering why both milepost 25.4 automatic and CP-DUMBARTON start as approach, it was likely just an easier way to meet the safety constraints as opposed to using Advance Approach or Approach Slow.
Caltrain's short signal blocks makes it somewhat easier to observe signal progressions as trains move down the line. Here we see the southbound milepost 25.4 automatic and CP-DUMBARTON absolute signals just south of the Redwood City platform. As the southbound train advances we see the Milepost 25.4 signal change to Advance Approach and as the CP-DUMBARTON changes from Approach to Advance Approach, the 25.4 signal changes to clear.
If you are wondering why both milepost 25.4 automatic and CP-DUMBARTON start as approach, it was likely just an easier way to meet the safety constraints as opposed to using Advance Approach or Approach Slow.
