One thing is certain, Caltrain has scored a marketing home run with their Baby Bullet brand, borrowing the aura of high speed rail and pointy-nosed aesthetics to convey an image of speed and efficiency. Unfortunately, there are a couple of problems with confusing the Baby and its namesake.
Myth #1: Speed
"We already have a bullet. We don't need another one!"
Baby Bullets look sleek, and they impress when they blast by, horn blaring. However, they are nowhere near as fast on average as the proposed high speed trains. Timings from San Jose to San Francisco:
- Caltrain local: 96 minutes - max speed 79 mph - average speed 29 mph
- Caltrain Baby Bullet: 57 minutes - max speed 79 mph - average speed 49 mph
- HSR: 30 minutes - max speed 125 mph (a.k.a "half speed") - average speed 94 mph
Ridership is very sensitive to total trip times and changing trains. Every second counts. That is the reason for terminating HSR in San Francisco, which has a large catchment area of potential riders.
Myth #2: Track capacity
"If HSR is running at half speed, let them just use the existing two tracks!"
Mixing trains with different average speeds on the same track reduces track capacity, measured in units of trains per hour (tph). A slow train must be given plenty of time to clear the tracks ahead of a fast train that follows; otherwise, the fast train will catch up to the slow train and get stuck behind it. While modern signaling systems allow 15 tph when speeds are homogeneous, today Caltrain can only manage 5 tph at rush hour because Baby Bullets and locals operate at very different speeds. Add HSR to the mix, and what little track capacity we have would collapse.
More tracks are needed along much of the peninsula to allow trains with vastly different speeds to overtake each other, thus freeing track capacity. This ultimately has benefits for local Caltrain service as well: with Baby Bullets allowed to operate on the new HSR tracks, local track capacity will increase, enabling more rush hour service to under-served stops like California Ave or Belmont or South San Francisco.
Never judge a book by its cover. Likewise, never judge a train by its pointy nose.