How punctual are our city trains?Posted: July 28, 2010
Actually they’re probably much less punctual than you think, no matter which major city you live in.
Consider the performance of Metro Trains, the new private operator of Melbourne’s metropolitan trains. Back in May, only 82.7% of services operated by Metro Trains ran on time.
This is well below the contracted 88% monthly punctuality target below which Metro is obliged to pay compensation. And it’s positively woeful compared to the 96% punctuality achieved by New York City’s commuter rail system last year.
The circumstances in May were probably unusual, but the standard 88% is hardly a high hurdle. Yet from a commuter’s perspective, it’s actually worse than this figure suggests.
The definition of on-time running agreed between Metro and the Victorian Government is a service that is within five minutes of the scheduled time. While this is actually an improvement over the six minutes grace that applied under the previous operator, it can be an eternity for commuters not yet inured to institutionalised lateness.
But it gets worse than this, much worse, because there’s another “nuance” to the way punctuality is measured. Although the 96% punctuality achieved in New York City is one of the best ever performances since records started to be kept, commuters still feel the reality is very different and vastly more frustrating.
Intrigued by this disconnect, the New York Times decided to undertake a review. The paper’s investigators:
“found that 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)”.
What is going on? The explanation offered by the Times for the contrast between the rosy official measure and travellers’ frustrating experiences 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. As Jarrett Walker at Human Transit explains:
“….. 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”.
As Walker 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), it seems likely the resulting figure for Metro’s performance in May would be truly appalling.
The “official” method of assessing punctuality measures something and no doubt does it well, it just doesn’t measure anything particularly meaningful to beleaguered commuters.