ST’s new 1st quarter 2010 ridership report is out. As ST was reporting monthly Central Link ridership through March, there’s no new information on that front. For other modes, though, from 1Q 2009 ST Express ridership was basically flat, while Tacoma Link was down 5% and Sounder declined about 7%. Overall, ridership was up 36% thanks entirely to Central Link.
However, Link’s on-time rate was a horrific 71% for the quarter, compared to an ST goal of 90%. An on-time trip, as I’ve complained before*, is defined to be one that leaves its terminal station less than one minute late. ST spokesman Bruce Gray explains that the 90-day quarter had a total of 35 days of maintenance work (mainly for noise reduction and WSDOT work); thanks to the limitations of the measurement system, all trains that deviated from the printed schedule (or weren’t run at all) were counted as late. Gray adds that ST is “not happy with the 70% rate” and on-time results have “gotten a lot better over the last month or so” as a lot of that maintenance work has wrapped up.
What’s more, Gray added that even under these conditions, 90% of trains were spaced within three minutes of their published headways. A maintenance delay that slowed everyone on the line, or truncated it at Sodo, didn’t necessarily mess up the spacing between trains. Indeed, I’ve argued before that when headways are short this is actually a much better measure of reliability.
Maintenance doesn’t explain all the late trips. The report also blames bus/train operations in the tunnel, which is unique in the world, and therefore a source of schedule risk. Ben’s going to have a more in-depth report on reliability next week.
*In that post, I cited a 99.5% reliability report for Central Link’s 3rd quarter, although no number was available in the 4th quarter. Gray wasn’t prepared to elaborate on the origin of the 3Q number, although he understands that what data was gathered in 2009 was not very reliable. Indeed, public Link schedules didn’t even exist until the 4th quarter, so it’s not clear how these metrics were defined.