Analysis
Media outlets reported on the impact to passengers of operators missing out stops to mitigate service delays, but did they properly assess the criteria? asks GARETH DENNIS
‘Station skipping’.
DOES the recent noise about station skipping really match its impact on the travelling public?
On April 16, BBC News went all-out with a story on station skipping - the practice of permitting a service to miss out one or more intermediate stops, either to minimise the delay to its arrival time at later stations or to alleviate perturbation elsewhere on the network.
While other reasons exist, such as diversions during engineering works or emergencies at stations, there is an argument that these represent a minority of cases when compared with those resulting from delays. In any case, the routine skipping of intermediate station calls can clearly be very disruptive for individual passengers.
In its article, BBC News reported on the number of trains skipping one or more stations per 1,000 planned services. However, while this gives a numerical comparison across the train operating companies (TOCs), it doesn’t paint a very clear picture of the problem with respect to the size of each operator… or the impact on passengers… or indeed whether this level of station skipping is “normal”.
That Govia Thameslink Railway (GTR) is at the top of the list should be no surprise - in 201617, passengers took 28% more journeys with GTR than with the next busiest TOC (South West Trains, now South Western Railway, SWR). This isn’t the story.
London and the South East has a very dense network with frequent services, where perturbation (delayed in-service and out-of-- service rolling stock) is common and can quickly spread back through the network. Conversely, the frequency of stations and services means that the impact to passengers of a missed station is reduced.
The reality is that as the railway network reaches its capacity, we are having to increasingly rely on this instrument in our operating toolbox, to avoid more widespread delays.
Britain’s rail network is the most densely travelled in the world (in terms of passengers per kilometre), after India, China and Japan - and that’s before we even consider freight. A more useful comparison would have been to first contrast the Britain’s skipping statistics with the figures from these (and other) countries.
However, considering the difficulty of attaining such numbers, the next useful comparison would be between the skipping rankings and the rankings of the TOCs by the number of journeys taken.
GTR and SWR are at the top of both lists, which is unremarkable. However, London Overground and Northern are way down the list of ‘skippers’, despite representing the third and fifth greatest number of journeys respectively. Great Western Railway and Greater Anglia also compare favourably, while Southeastern and ScotRail are about where you would expect them to be given the number of journeys they represent.
On the other hand, the TOCs that appear to be performing very poorly by this measure are TfL Rail, Arriva Trains Wales and (most surprisingly) Hull Trains. Despite representing a smaller number of journeys, these operators are high up the list of ‘skippers’.
Even then, this isn’t the whole picture.
If you normalise the station skipping numbers by the passenger kilometres for each TOC, the big hitters (Govia Thameslink Railway, South Western Railway and Southeastern) remain in the top three. This is also the case if you look at the average number of journeys affected by station skipping.
However, unlike the by-service measure of the skipping problem employed by BBC News and others, ScotRail is consistently fourth in the list if you normalise either by passenger kilometres or by the number of affected journeys.
Scotrail and Northern both operate a large variety of services, ranging from long-distance rural to high-density urban services. ScotRail represents 13% fewer journeys than its English counterpart, yet it ranks above Northern in terms of normalised station skipping figures.
This perhaps explains why complaints seem to target the Scottish operator, and why (as recently announced by Managing Director Alex Hynes) ScotRail has modified its policies to “virtually eliminate” station skipping. Still, ScotRail’s figures aren’t hugely noteworthy.
Hull Trains, while being the worst relative offender for station skipping, carries relatively few passengers, so the impact of skipping is small (only 24 passenger journeys a day, on average).
Northern performs exceptionally well if you look only at the number of skipped services, but it ranks further towards the top of the ‘skipper’ rankings if you look at the normalised figures.
Any number of conclusions can be drawn from the figures once you start to make useful comparisons (particularly if you pay less attention to rankings and more at the numbers themselves), but the London operators being the most common station skipping offenders is not one of them.
In publishing such figures, there is an argument that media outlets such as the BBC should be careful not to skip due statistical diligence when writing its headlines. ■ Gareth Dennis is an engineer and writer, specialising in railway systems. As well as roles in engineering consultancy, he leads the local section of his professional institution and is a lecturer in track systems at the National College for High Speed Rail. Follow him on Twitter: @garethdennis