You are correct—well, obviously, you're correct—in your statement about rail performance. I wouldn't necessarily say 'declining', but it has certainly plateaued, and that would certainly be the case on Wales and cross-borders, whereas on CVL, we've pretty much kept a good service going.
I'll talk a bit more widely about this, if it's okay, but on WCB the main issue we have had has been linked to storms—that's the first thing. So, we have had three significant storm events that have impacted each of the three last periods, either in the rail period, or the clean-up has been in the rail period. Therefore, for our colleagues at Network Rail, removing flooding, dealing with wash-outs, dealing with points that have failed as a result, dealing with significant power cuts, which they have also had, has been largely what has driven that.
The other thing, though, that we are dealing with at the minute is a slightly lower number of CAF units, new train units, coming out of the maintenance facility per day than we would like to see. So, we are roughly four units short a day. That does not mean we are cancelling in the way that we were in the past. What it does mean is that, occasionally, we are short-forming a service with fewer carriages than we would want to have on there, which I think has led to a plateauing, as I said, rather than going backwards.
It's an area we're very focused on. It's an area, though, that we ourselves cannot sort, and we need CAF to come to the table. In essence, what I need to do is to get CAF, who are a very competent international rolling stock provider, to provide rolling stock in Wales to the same level of excellence that they provide in their best plants around the world. That's the journey that we are on.
If I might continue, just briefly, on core Valleys lines, core Valleys lines are, as I said, performing relatively well, but we are facing a strategic challenge that, maybe, at another time, it would be good to discuss with the committee. That is around what is the right metric to measure ourselves against. So, if I can just explain that a little bit, certainly on the core of the core Valleys lines, you will see now a service between every four and six minutes. Therefore, if we cancel a service—we would rarely cancel the full service, but you might see a train running fast through a number of stops to catch up—the impact of cancelling the service on the individual, me included, quite often, can be quite minor, because people are only waiting four to six minutes for the next train. That's on core Valleys lines. If you did that approach in rural Wales, where you've got four services a day, you'd have a horrendous problem.
The difficulty we have got at the minute is that we are measuring the performance of all of our networks on the same set of metrics, and, increasingly, as we've got better overall—and this was an example of one of the things I said I want to get into the detail of—it can drive perverse behaviours in our managers, because our managers will look to hit the performance targets, and if we say, 'Hit passenger time lost, but don't bother about cancellations,' they'll cancel lots of stuff off. If you say it the other way, they'll go the other way, and we need to get into the detail of what's important for different lines. And that, alongside better availability of CAF, continuing to work with Network Rail to get climate change resilience and the introduction of electric trains, we'll see the performance improve—I'm pretty confident of that—or improve again.