Demand for Caltrain is standing room only during rush hour, with 33% of traffic living in Palo Alto and working in SF.
Caltrain has two primary constraints, neither population-linked: diesel trains accelerate badly, and freight track scheduling.
Diesel trains are theoretically being swapped for electric, which will permit the trains to stop and start more efficiently. They predict one additional train during peak rush hour per day for this improvement, iirc.
Freight traffic consumes a fixed amount of rail time, focused primarily on the "one hour between" segments of the schedule. Increasing frequency can only occur within existing scheduled route times, and cannot disrupt that freight traffic.
Caltrain has two primary constraints, neither population-linked: diesel trains accelerate badly, and freight track scheduling.
Diesel trains are theoretically being swapped for electric, which will permit the trains to stop and start more efficiently. They predict one additional train during peak rush hour per day for this improvement, iirc.
Freight traffic consumes a fixed amount of rail time, focused primarily on the "one hour between" segments of the schedule. Increasing frequency can only occur within existing scheduled route times, and cannot disrupt that freight traffic.