20 August 2011

CBOSS vs. Metrolink PTC

UPDATE 8/22 - There are a couple of additional points that require clarification.

(1) It is claimed that Caltrain's CBOSS budget is so high because it is a turn-key system provided entirely by the vendor, whereas Metrolink's PTC is being done partly in-house. But Metrolink's in-house PTC costs are included in the $202 million estimate (see page 7: $77M Metrolink, $90M vendor, $30M contingency). This does not make the comparison any more favorable to Caltrain.

(2) It is claimed that the standards for high-speed rail PTC are immature. Not so; the requirements are found in pages 723 to 825 of the HSR system requirements report (as of August 2010) as well as in HSR technical memoranda TM-3.3.1 ATC System Concept and others in the 3.3.x series. The kicker (as far as Caltrain is concerned) is that those documents clearly state that "the technology must already exist as part of an operating system with proven experience worldwide on at least one high speed passenger railway"... in other words, CBOSS need not apply, and ERTMS (now being installed by sensible commuter rail operators in places like Rio de Janeiro and Auckland) is most welcome.

ORIGINAL POST - The FRA's push to impose positive train control on all U.S. passenger railroads was triggered by the 2008 Chatsworth collision on Metrolink, in which 25 people died and 135 were injured. Not surprisingly, Metrolink's effort to meet the FRA's December 2015 deadline for PTC implementation is in the national spotlight. If a PTC success story was ever needed, it would surely have to be in Los Angeles.

Metrolink is very much like Caltrain, in that it operates diesel-powered double-decker commuter trains that occasionally intermingle with freight trains. Weekday ridership is similar at about 40,000 trips. Being in the same state, Metrolink's regulatory environment is the same as Caltrain's. One struggles to think of "unique local conditions" that might make Caltrain materially different from Metrolink.

According to Metrolink's funding plan for the project, the total budget for Metrolink's PTC system is $202 million, an amount now fully funded. Not to be outdone, Metrolink plans to complete the system a year before the federal deadline.

Here is a summary comparison table of Caltrain and Metrolink.

System Route Miles

Fleet Size (Locomotives + Cab Cars)
Weekday Ridership
PTC Total Budget
$202 million

$250 million
PTC Planned Completion
end 2014
end 2015
PTC Funding Status
$202M (100%)
<$100M (<40%)
PTC Interoperable with Freight

You might think that for the quarter-billion dollar price tag of CBOSS (Caltrain's PTC project), one would get something extra, like future-proof compatibility with high-speed rail. But alas, no. At a recent Friends of Caltrain meeting, deputy CEO Chuck Harvey confirmed that due to schedule pressure, CBOSS development would forge ahead without any regard to high-speed rail, and that HSR would have to "pay to play," with a possible requirement of "dual fitment," i.e. two separate PTC installations on-board each high-speed train in all of California. Never mind that the statewide HSR fleet would dwarf Caltrain's.

So, if HSR compatibility is not on the agenda, then what makes Caltrain any different than Metrolink? Why is CBOSS going to cost millions more than a PTC system for six times the route length and nearly twice the fleet size, to be delivered a year earlier? Why not realize economies of scale and pattern Caltrain's PTC project after Metrolink's, which has far more stakeholders in a successful outcome?

That is a quarter-billion dollar question.

13 August 2011

Corridor Capacity Study, Free Edition

You may have heard that Caltrain is working on a corridor capacity study, to see how much high-speed rail traffic could be accommodated on the corridor without adding too many passing tracks or destroying commuter service quality.

While we wait for the outcome of this study, below is a decomposition of the problem into a range of possible solutions.

Some solutions have very little downside for HSR or Caltrain service:
Other solutions require compromise between the needs of high-speed rail passengers, the needs of commuter passengers, and the needs of surrounding communities.
  • Slow down HSR, with lower top speed and all stops (Millbrae and Redwood City) made by all trains
  • Close low-traffic Caltrain stations such as Atherton and Hayward Park
  • Make peak-hour trains skip more stops-- which unfortunately denies frequent commuter service to communities precisely at the times when it is most needed
  • Build additional grade separations wherever four tracks are required
Before we make any of these painful compromises, however, the most effective measures that do not require compromising service quality should be prioritized and vigorously pursued.

If one had to bet a six-pack of one's favorite microbrew (worth several orders of magnitude less than LTK Engineering's consulting contract), the outcome of the capacity study is likely to be:
  • With 6 Caltrains per hour during the rush, spare capacity available for HSR is minimal on the existing tracks
  • Capacity can be increased most effectively by matching train average speeds, i.e. slowing down HSR and/or speeding up Caltrain
  • HSR trains will probably average no more than 60 mph between SF and SJ
  • A mid-line overtake facility between Whipple @ Redwood City and 9th Ave @ San Mateo (requiring minimal new grade separations) would improve peak corridor capacity from 6 to 8 tph
We shall soon find out if we got our money's worth.