I am disappointed to see the continuing absence of detailed Central Link service information from Sound Transit publications and its website. Also, schedule information was removed from OneBusAway and replaced with headway information*, a decision that the agency made a few months ago.
While Link provides very frequent service by Seattle standards (and that is a pretty low standard, in context of big city transit systems), it is not frequent enough to completely disregard a schedule that lists specific departure times. The Transit Capacity and Quality of Service Manual, considers service headways less than 15 minutes as “frequent service”. It states that between 10 and 14 minute headways, passengers do consult schedules to minimize their wait time. Any headway below 10 minutes, most people don’t bother with schedules, since the waiting time is minimal and is often assumed to be half the headway on average. This statement is supported by empirical research by Bowman and Turnquist and seems to make “common sense.”
Knowing the time a train is scheduled to depart, is necessary in planning trips that involve transfers to other services be it a bus, Sounder or ferry, especially to services that are not frequent. Trip Planner does this for us automatically but not everyone has access to it, some prefer manually planning, and some just want to know the departure time of a specific train. If Trip Planner has the information, why can’t we all easily see that information?
More after the jump.
One reason given for not listing the departure times has been concern for reliability. Central Link’s on-time performance has been improving, from a horrific 71% to 86.60% for the 4th quarter of 2010. It is still below the minimum of 90%. By comparison, Metro’s on-time performance target is 80% and with actual performance around 75-80% and ST Express bus is around 88.53%. Despite similar performance, Metro publishes a complete timetable for the 7, not just a summary that says “buses depart every 10 minutes from 6 am to 6 pm and every 15 minutes at all other times.” Similarly, for real-time information, it’s helpful and reassuring to know that “oh, I just missed the train by 3 minutes but the next should arrive in about 7 minutes.” OneBusAway works well most of the time for buses in mixed traffic, without the help of GPS, so what’s the deal with it not working at all for trains on a fixed track in an exclusive right of way?
While Sound Transit says they “want to give [their] patrons the most accurate information that [they] can”, it is not an excuse to leave their customers in the dark and make the system less useful and less attractive by increasing uncertainty and anxiety. With Link intended to be the regional transit spine in a transfer-based system, how can people plan their transfers without the necessary information?
* Brian Ferris tells me the schedule is still in the raw data feed for this service change but it may be discontinued, as OneBusAway now displays headway info at request of the agency.