Phased Implementation

UPDATE 4/30: A more detailed memo has now been posted for approval by the CHSRA board this Thursday. It describes the first phase, the last phase (full four-track build-out), but nothing in between describing what all these intermediate phases might actually look like.

Original Post: The California High-Speed Rail Authority has now posted their description of what 'phased implementation' means for the peninsula. The Phased Implementation Fact Sheet and Phased Implementation Q&A are the first documents posted to the CHSRA's San Francisco - San Jose document library following an eight-month dry spell. Look for this to become the new buzzword.

Mind The Service Gap

Having cobbled together additional funding for the next fiscal year, Caltrain has published a revised 76-train timetable that is now proposed to go into effect this summer. This timetable is an improvement over the previous proposal, a controversial 48-train peak-only timetable (previously analyzed here) that caused an outcry up and down the peninsula. To save $3.3 million in annual operating costs, the 76-train timetable cuts ten trains from today's peak service by eliminating the Baby Bullet express trains and substituting fewer limited-stop trains.

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

And now, the proposed 76-train timetable:

• 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

Wait, is that right? One-hundred-and-four?

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)

What happened in the new 76-train schedule can be understood by taking a closer look at the numbers. Some best trip times got a bit worse, due to the lack of Baby Bullets; some mean wait times between trains got a bit longer, due to 4 rather than 5 trains per hour; but the maximum service gaps dropped precipitously, enough to outweigh the other effects when considered for all origin and destination pairs, even after weighting the results by ridership.

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.
  

So should the Baby Bullet be scrapped? That depends on one's beliefs... namely:

• 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.
  

When all is said and done, the choice between the proposed 76-train timetable and preserving today's timetable comes down to $3.3 million. That amounts to a mere 3 percent of Caltrain's annual operating budget, and makes this particular decision pale in comparison to far more pressing issues such as providing Caltrain with a dedicated funding source and advancing the electrification project.