How does this new 76-train timetable stack up? We put it through the Metricator to extract key rush-hour trip time statistics, using the same methodology as before... with the expectation that the results might not be so great.
First, as a reminder, we consider the current timetable. The basis of comparison is today's 86-train-per-day, 5-train-per-hour timetable, to which we assign a score of 100.
- Input timetable file (tab delimited text)
- Metrics that matter table (318 kB PDF)
- Effective trip time table (35 kB PDF)
- Origin & Destination service score table (539 kB PDF)
- Overall rush hour service quality score: 100
- Input timetable file (tab delimited text)
- Metrics that matter table (344 kB PDF) -- also compared with Caltrain 2010 (328 kB PDF)
- Effective trip time table (35 kB PDF) -- also compared with Caltrain 2010 (38 kB PDF)
- Origin & Destination service score table (165 kB PDF)
- Overall rush hour service quality score: 104
Did You Say Better?
Four trains per hour with no Baby Bullets is better than five trains per hour with Baby Bullets? Surely this shocking result must be wrong?!? The short answer is no, the numbers don't lie.
The long answer requires a little bit of background discussion. You see, the Baby Bullet has a dirty little secret. In order to achieve such stellar trip times, other trains must clear the tracks ahead of it, because if the express ever caught up to a local, then it would no longer be an express. In practice, that translates to very long service gaps just before a bullet comes through. Service gaps (i.e. how many minutes pass between two successive departure times for a given origin & destination pair) are an important component of the convenience of taking the train. In these calculations, an effective trip time is computed based on the following sum:
- 70% of the average trip time
- 30% of the best trip time (to favor express service)
- 20% of the mean wait between trains (far less than the random arrival figure of 50%)
- 15% of the maximum service gap (to penalize very large gaps between trains)
Various other observations on this new timetable:
- Rush hour service is significantly improved for stops such as Burlingame, Lawrence, Sunnyvale, Cal Ave, etc. as can be readily observed in the effective trip time savings. Note these are all the stops where service was degraded when the Baby Bullet service started.
- Closing Hayward Park makes sense. Despite all the talk of transit-oriented development at this location, the fact remains that ridership is so low that wasting three minutes of everybody else's time to stop there isn't worth it. Besides, the station will be less than a mile away from Hillsdale when that station is moved to the north, as long planned.
- There is a long and awkward service gap departing San Francisco between 6:45 and 7:30 PM.
- San Bruno, where Caltrain is investing a nine-figure amount to rebuild the station, is left with dismal rush hour service.
- Express service isn't inherently bad. It adds the most value when trains ahead don't have to get out of the way, i.e. there is a way to overtake trains without penalizing local service by imposing large service gaps ahead of the express. There exists a six-train-per-hour timetable that scores 145... but it requires a mid-line overtake. That's why a phased implementation of future peninsula corridor improvements should include a mid-line overtake facility as extensively discussed here and here.
- Do service gaps matter? The opinion presented here is obviously that they do. Caltrain seems to consider trip time only in terms of how long a passenger spends on the train (see page 16 in their presentation), without much regard to how long they might spend on the platform waiting for the next train. The underlying assumption is that every passenger builds a routine around the same train every day, and shows up just in time for that train.
- How valuable is the Baby Bullet brand? There is reality, and then there is perception. People buy a product based on their perception, and the Baby Bullet undeniably has a certain cachet. The Baby Bullet has been marketed very effectively, to the point that most people believe that Baby Bullet trains are faster than they actually are. That belief doesn't show up in the raw metrics, but it does enter into people's choice of transportation.