How many passengers per minute can a bank of Myki ticket gates process at a Melbourne railway station in morning peak? In the case of Flagstaff Station it doesn’t seem to be enough, and the reason might be the cycle time of the gates – but what about some hard data?
For a ticket gate morning peak at a City Loop station is more intense than afternoon peak: at the start of the day waves of passengers alternate with quiet periods as trains arrive on the platforms every few minutes, but in the afternoon passengers form a steady procession as they arrive on a random basis from their individual workplaces.
So how long does it take a set of ticket gates to allow a single passenger to exist the station? Back in June 2012 I also did some some limited counting of my own at Flagstaff station:
My stopwatch says a successful #myki frankenbarrier touch off takes between 2.27 and 3.66 seconds.
— Marcus Wong (@aussiewongm) July 1, 2012
Wednesday factoid: you can get 20.3 #Myki users a minute through a single Frankenbarrier (assuming no swipers or tappers)
— Marcus Wong (@aussiewongm) June 26, 2012
It resulted in the following unscientific data:
- 21 persons per minute: all using Myki (based upon 7 passengers in 20 seconds)
- 13 passengers in 60 seconds: 1 using Metcard, 12 using Myki, and a Myki user who gave up
So how many passengers through a ticket gate per minute is considered best practice elsewhere in the world? The first source of statistics I found was from the Rail Safety and Standards Board (RSSB) of Great Britain, who write the following in their Rail Industry Standard for Automatic Ticket Gates at Stations document:
For Automatic Ticket Gates (ATGs) already installed a passenger flow rate of 25 passengers per minute for each ATG has been recognised as best practice. This is an average figure which allows for gates not used to the design maximum and takes account of the additional time that new card readers require for the smartcard technology
While the RSSB thinks the use of smartcard readers slows the flow of passengers, issue 14 of the European Public Transport Magazine “Mobility” suggests otherwise:
Oyster has been a phenomenal success for TfL. The system has actually relieved congestion on London’s public transport system, in particular during the morning and evening peak periods. It allows 40 people per minute to pass through ticket gates, 15 more than with magnetic stripe tickets.
Meanwhile in Japan, this article in The Economist suggests their rail operators are even more optimistic about the number of passengers their ticket gates can process:
Many of the keitai-credit systems rely on a NFC chip called FeliCa, which was developed by Sony. This chip is embedded in both NTT DoCoMo’s wallet phones and the new Pasmo system. The chips have to work rapidly and reliably, says Ted Osamura of FeliCa. For instance, the railway operators have insisted that their system can admit 60 passengers a minute through each ticket barrier.
So what are we stuck with back in Melbourne? I eventually found some figures for the Metcard system buried in the infrastructure leases signed in 1999 between the State of Victoria and the private train operators – the section is question was page 2 of this document:
Underground stations were designed to handle crush-loaded trains operating at 2.5 minute headways. Handling capacities have been affected by subsequent commercial development, and barrier deployment (in operational mode 20 persons per minute can be processed by each barrier, suggesting capacities for Melbourne Central of 20,000 passengers/hr, Parliament of 18,000 passengers/hr,and Flagstaff of 9,600 passengers/hr)
With the rollout of Myki almost complete along with the removal of the ‘Frankenbarriers’ from City Loop stations, where are we today?
For more up to date data, the Victorian Rail Industry Operators Group ‘Railway Station Design Standard and Guidelines‘ document comes up with some rather wishful sounding passenger throughput figures:
Gateline length flow capacity shall be based on circulation. Passenger flow rates can be up to 75 passengers per minute based on passengers walking at an average speed of 1m/s, distance between passengers of about 800mm and smart card processing time of 0.8s per smart card.
To determine the real world performance of the new Myki ticket gates, I did some data collection of my own (on a day where the gates were working as normal – not broken down and needing technical assistance):
Cycle time of #Myki barriers at Flagstaff station is somewhere between 1.6 and 3 seconds. (Assuming they aren’t frozen)
— Marcus Wong (@aussiewongm) November 8, 2012
Here is the complete dataset, collected around 8:45am on a weekday morning at Flagstaff Station. I watched a single ticket gate and clicked my stopwatch every time a passenger successfully touched off, only timing when a queue existed, so that I was counting the true minimum cycle time and not counting ‘empty’ time between passengers.
With an average touch off time of 2.97 seconds in my dataset, a fraction over 20 passengers per minute can pass through a Myki ticket barrier. I don’t call that an improvement!
There is actually a very simple way for passengers to increase the overall flow rate of the ticket gates – the obvious one is making sure they have their ticket ready before approaching the exit!
A second and less known trick is ignore the passenger in front when presenting your Myki to the reader, and instead touching off as soon as the ‘Please present your card’ message reappears on the screen – the gates will cycle closed then reopen after a moment or two, leaving them ready for you to walk through.
Getting the timing right is difficult the first time you try but isn’t impossible – my set of data saw three passengers in a row achieve ~1.6 second touch off times, which equates to a 37.5 passengers per minute flow rate if such skill could be sustained by every passenger.
In the case of the original Metcard gates, a similar process worked – as soon as the ticket validator slot lit up green again, you could pop your Metcard through and the gates would close then reopen, all before you had the change to walk through them. The only exception was the Frankenbarrier: prematurely presenting a Myki to the reader was a recipe for disaster that might leave you with a touched-off card while stuck behind a closed gate.
These figures are ‘near enough’ timed using a stopwatch app on my mobile phone, and are in no particular order. With only 34 data points collected over around 2 minutes at one time of day, one would need to collect a lot more data to do any serious data analysis with it.
|Cycle time (seconds)|