Based on quarterly figures from Public Transport Victoria (source: ABC Fact Check)

Earlier this week ABC TV News did a ‘fact check’ on the Napthine government’s claim that Melbourne trains are more punctual now than they were prior to the last election.

The checkers concluded that Dr Napthine’s claim checks out.

With punctuality running at over 92 per cent across the Metro network, trains are more often on time now than under the previous Labor government.

They took into account concerns that improved punctuality might’ve been achieved by the operator’s practice of skipping stations (see What’s better: a train that’s late or one that doesn’t get there at all?). They say that over the last two years, “less than half of 1 per cent of all trains skipped stations to improve punctuality”.

Commenters on the ABC’s web site however point out that the checkers failed to take into account “padding” of timetables. Blogger and public transport advocate Daniel Bowen elaborates:

Comparing times on the Frankston line: during peak (morning inbound, afternoon outbound), and when it’s quieter (Sunday morning inbound and outbound), we can clearly see that running times have increased — 3-4 minutes was added in 2012. It’s a similar story on other lines.

There is now so much padding, he says, “that trains regularly sit idle at stations waiting for the timetable to catch up…or (accidentally) depart before their scheduled time. So it’s hardly surprising that punctuality has increased”.

I expect that explains in large measure why travellers continue to be disgruntled with the real time performance of the rail system even though the supposedly objective indicators say things are on the up and up and, indeed, have never been better.

I think there’s another factor, though, that also helps explain why travellers are apparently blind to the facts and, it seems, so irrationally ungrateful.

Prior to the last state election in Victoria, I wrote about a report in the New York Times that travellers were unhappy with the city’s train system even though punctuality was running at 95% (see How punctual are our city trains?). It’s worth revisiting in the context of this issue.

The paper’s reporters wrote that (95% of trains are on time; riders beg to differ):

The official figures for on-time performance, often used as a promotional tool, contrasted sharply with the experience of tens of thousands of passengers who regularly ride the trains at peak hours. In fact, the most important trips for daily commuters, those that can make or break breakfast with a client or dinner with a spouse, experience far more delays than the statistics may let on…

On weekday mornings, 1 in 10 trains entering Pennsylvania Station arrived late, two-thirds by 10 minutes or more. At the peak of the rush, from 8:30 to 9:30 a.m., about 25 percent of New Jersey Transit trains entering Manhattan arrived late; about 2 in 5 of the late trains were tardy by at least 15 minutes. (The trains’ scheduled runs are a little more than an hour on average).

How could there be such a disconnect between the rosy official measure and travellers’ frustrating experiences?

The explanation, says The Times, is that punctuality is measured across all services whereas the great bulk of passengers travel in the peak when the headway between trains is much lower.

Jarrett Walker at Human Transit explains the technicalities:

Peak hour commuter trains are most likely to be late because they run when the system has the least margin for error. And since most riders of commuter rail are on the peak, most riders experience the system at its least reliable.

In short, 96% on-time performance doesn’t mean that 96% of customers get where they’re going on time — only that 96% of trains did, counting nearly empty trains at 10:00 PM when there’s plenty of spare capacity on the rails, and a lot fewer causes of delay.

He suggests the appropriate measure of punctuality would start with something simple like an average of the time lost by each train weighted by the number of passengers per train.

If this calculation were done for Melbourne (and I daresay this holds for most other capital cities), I think it might show the real figures for Metro’s performance are truly appalling (although punctuality might still be ‘less worse’ under the Napthine government. Or not).

The “official” method of assessing punctuality certainly measures something and no doubt does it well; it just doesn’t measure anything particularly meaningful to beleaguered commuters. In this case the ABC’s checkers don’t appear to have checked the facts.