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Leigh Holcombe

Many municipal buses have onboard computers that let an operator know if s/he is "hot" (ahead of schedule) or "cold" (behind schedule). Because of the way operator performance is measured, they will often drive less safely if they are cold. I wonder if this might be too big a cost for punctuality.

Interestingly, the biggest reason by far that buses are late is traffic - traffic largely caused by single occupant vehicles. In theory, the more successful a transit system becomes, the more of its own logistical problems are solved.

Alon Levy

SBB has switched to a customer-centric definition of on-time performance. It counts customers as late if, due to train delay, a missed connection, or both, their trips have gone more than three minutes over schedule. By that new standard, the on-time performance is about 87%.

(By the way, I heartily recommend you go to SBB's English website, which features a lot of interesting information about the company and its practices. The only other non-English-speaking company I can think of that is this forthright in English is JR East.)

Rob Fellows

There is a lot that could be done with location information that's becoming more ubiquitous in modern transit agencies. For example, if a smart bus is given data about the location of its leader and follower, it wouldn't be difficult to present a display for the operator showing how close he or she is to halfway between them. Similarly, headway-based signal priority requests could be turned on or off to optimize headway rather than schedule using the same information.

The primary challenges are not technical, they're philosophical. Can agencies adjust their thinking to prioritize headway vs. schedule management? Will they give operators the tools they need to manage their headways?


NOTE: This post was updated at this point in the comment thread, but all the preceding comments are still relevant to the revised post.

Eric Fischer

The fact that the definition of what it means for Muni to be on time was part of Proposition E is part of the problem -- it means they can't change from a schedule-based definition to something else without a vote of the public.

On the other hand, the proposition says nothing about what they actually have to include in their published schedule, so I think it is kind of surprising that they haven't altered the schedule to match reality instead of trying to make reality match the schedule.

capt subway

The OTP bugaboo has also run amok here in NYC on the NYCT subways. The former president of NYCT, Harold Roberts, was obsessed with OTP to a truly pathological degree and to the exclusion of almost everything else and wanted to achieve nothing less than 100% (LOL). He just didn't understand that on a system such as the NY subway, with many lines operating with headways as short as 4 minutes all day long OTP just isn't a good indicator of service quality. Far more important are frequency, adequacy (except during the rush hours are there enough trains to comfortably carry all the passengers?) and even spacing between trains.
The idiots in charge here in NYC actually eliminated service in the hair-brained belief that too many trains were causing congestion on the line, which in turn caused lateness.
Oh rest assured they also added huge amounts of running time to paper over any lateness. In sum: less is actually more, slower is actually faster.



As a matter of fact Muni is doing these things.


capt subway

This is not surprising. But, without sounding patronizing or "elitist" this is the whole problem with the CA style of government by proposition. In this case most passengers do not understand the nuts-n-bolts of daily transit operations. So to most of them OTP sounds like a great way to measure performance. It's an easily graspable concept. Try explaining through-put, even spacing, headways, service adequacy, vehicle requirements and turn-around time, crew requirements, etc. to the average voter.


@ Steve. Thanks. I've added a sentence linking to the SFMTA policy. Keep us abreast of how it goes.

Alon Levy

By the way, the aforementioned SBB website is here. Follow links to the passenger rail annual report, which talks about investment, on-time performance, and other issues.


I agree that for the customer waiting at the stop, a headway maintenance system would be beneficial. But a 10 minute frequency where all buses are 10 minutes late is not as good as one where they are on time - it is (presumably) taking the passengers longer to reach their destination than scheduled. And a pure headway maintenance system would penalize good bus drivers (and their passengers) who might have to drive especially slowly so as to keep their distance from a bus driver who drives especially slowly due to lack of effort or excessive socializing. A headway maintenance system might be OK if it worked with bus loading to allow heavily loaded buses to proceed and lightly loaded buses to hang back.

Jarrett at HumanTransit.org

Chris.  I'd make a distinction between buses being late relative to a schedule, as opposed to taking longer than they should to complete a trip.  A headway maintenance system still focuses on fixing the latter problem, but quits worrying about the former one. 


"...the actual gap between trips -- which is all that a customer notices on high-frequency service..."

This is only true if: a) The customer does not need to make any transfers, b) does not need to be anywhere at a certain time, and/or c) is willing to leave far earlier than theoretically necessary.

Several years ago, I had cause to go to another city in the Metro area every day for several weeks. This involved one or two buses, followed by a train, followed by another bus. Unless I left home a full hour earlier than called for by the theoretical service schedule, I would almost always be late, though by a different amount every time. Sometimes a scheduled run would simply never come at all, but mostly it was a matter of missing connections because a bus was running late. In the end, I actually found it more reliable and time-effective to simply bicycle the 15 miles!

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the firm

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