Note: This post was starting to get a bit long, so I’ve split it up into 3 parts. Here is part 1.
A new Cityrail timetable is released each year, and while usually this means adding a couple of extra services or moving some trains a few minutes either way, this year’s will be the most dramatic change since the 2005 timetable.
“a brand-new rail timetable is being written from scratch, and will be released this year to provide more express trains, quicker travel times and ultimately improve the customer journey” – Gladys Berejiklian, Transport Minister (15 January 2013)
Writing a timetable is a balancing act involving trade offs. One way of looking at it is by breaking it down to 3 different variables, and a decision that needs to be made on which of these 3 to prioritise. Given the problem of limited resources, you need to pick two of those three and forget about the third. If you try to get all three, then you might end up with only one. Those variables are:
- Capacity – the number of trains that can be run on a particular track of rail line per hour
- Flexibility – the ability to get from A to B without having to transfer to another train (generally this means being able to get from anywhere to the CBD, and vice versa, on a single train)
- Reliability – how well trains run to timetable (rather than being delayed or cancelled)
Take the 2005 timetable as an example. Cityrail had become notorious for its unreliability. On time running data shows that in 2003, 80%-90% of trains ran within 4 minutes of the timetabled time. But in 2004, this figure had dropped to 50%-60%, and remained that way until mid 2005 when 2 things happened. First, on 1 July 2005, on time running was redefined from being within 4 minutes of the timetable, to within 5 minutes of the timetable. This resulted in an immediate statistical, though not actual, improvement to reliability (from 65% in June, to 77% in July). Then in September a new timetable was introduced, cutting 1,350 weekly services and slowing down the remaining services. The government had decided to cut capacity in order to improve reliability, while maintaining flexibility. And it worked, with on time running improving right away (from 78% in August, to 94% in September). It then stabilised in the low 90% range. While many complained about the longer journeys and lower frequency of trains, the 2005 timetable did finally return Cityrail to a reliable service.
Fast forward to today, and on time running is again on the decline. This time it has been caused by overcrowding on trains, leading to higher dwell times on major stations. This overcrowding is in turn due to rising demand for public transport, and also a lack of capacity to deal with the higher demand. Ironically, one of the biggest constraints on capacity was the timetable changes from 2005. Clearly, the 2005 timetable has run its course and needs to be revised again. Whereas last time the government chose flexibility and reliability over capacity, this time it looks to be opting for more capacity at the expense of flexibility in the hope of reverting to improved reliability.
These problems are not exclusive to Sydney. Melbourne has seen similar problems, and has also been tackling it via a more simplified, albeit less flexible, rail network. The video below outlines these problems and the solutions to these problems from Melbourne’s perspective.
Note: You can also get additional capacity by building new infrastructure. But the problem of limited resources and the trade off mentioned earlier still exists. The difference is you now have more resources to allocate between those 3 priorities, but a choice will still need to be made on how to allocate them.