Think the idea here is to highlight how punctual (or not) certain trains are over the last few weeks, and enable you to avoid those regularly delayed trains. I

Think the idea here is to highlight how punctual (or not) certain trains are over the last few weeks, and enable you to avoid those regularly delayed trains. It's not meant too identify individual train journeys that were late; Having a filter suggested would only work for trains that were >30mins late / cancelled, which is going to be exceptional and therefore not very useful for the main purpose of the site.