24 January 2020

Electric Timetable Contest

The coveted Takt Cup
Timetable planning has long been a staple of this blog, with the support of rapid prototyping tools like Richard Mlynarik's excellent Taktulator, a calculator for "Taktverkehr," the German term for clockface timetabling. While it may take a few minutes to learn how to use the tool, you can easily punch in a stopping pattern into the Taktulator to get an instant score, based on well-researched quality metrics and train performance calculations described here almost a decade ago. The service quality score is normalized so that the 2011 timetable, not much different from today's, earns 100 points.

Working back from its long term service vision, Caltrain has started planning for the near term timetable change that will occur with the start of electric service. Through a process of elimination, Caltrain has settled on two candidate service patterns, each with six trains per peak hour per direction, linked below in the Taktulator. You can verify that the resulting string line diagrams match extremely closely with the last couple of slides in Caltrain's presentation.

Two Zone with Express
Score: 123.3
Fleet: 13 EMU + 7 diesel

Distributed Skip Stop
Score: 124.1
Fleet: 13 EMU + 7 diesel
This timetable has a bit of a "can't get there from here" problem.

Can YOU beat those scores with a better concept?

Of course, scores depend on the assumptions you make. If you assume that the downtown extension is built into San Francisco Transbay, that all the diesels are replaced by EMUs, that dwell times are shortened by system-wide level boarding, that operating practices are reformed to allow better punctuality with less padding of the timetable, that terminal turn times are shortened to match foreign practice, and that a cross-platform transfer station is built in Redwood City with a short four-track section from just north of San Carlos into Redwood City (most of these contemplated in Caltrain's long-term planning), then you can set a sky-high score. In fact, using the Taktulator, you can even quantify the service benefit of each separate improvement. If we're allowed to dream, surely this is one of the most efficient:

Richard's Finest
Score: 230.2
Fleet: 16 EMU

Unfortunately, for the start of electric service in 2023, we'll have to settle for a bit less. There is no service to San Francisco Transbay, there is a fleet of 19 EMUs available of which you probably don't want to operate more than 17 at any given time, dwell times are still long (for simplicity, assume 45 seconds everywhere), timetable padding is ample (assume 10%), terminal turns are slow (assume 15 minutes), and there are no expanded stations or passing tracks. So, with those assumptions input into the Taktulator, can you beat Caltrain's score and win the coveted Takt Cup?

Please post your suggested Taktulator timetables and scores (and your supporting rationale) below in the comments. In your comment, use a clickable hyperlink, in the format <a href="your-taktulator-link">your timetable title<\a>, for brevity and clarity.

Here's my first entry for this contest, to kick things off:

Silicon Valley All Stop
Score: 126.9
Fleet: 17 EMU + 4 diesel

This improves on Caltrain's concept by admitting what census data and Caltrain's presentation tells us: all of Silicon Valley has enormous ridership potential, and running skip-stop express service south of Menlo Park is harmful to overall service quality. In short, the Baby Bullet is bad. This timetable also makes better use of the EMU fleet, as was intended when additional trains were ordered, by running 5 EMU + 1 diesel per hour per direction, instead of 4 EMU + 2 diesel.

Can you beat my score subject to the assumptions above?