[Symbiote]

The opening of the Elizabeth Line was partway through the statistic period used here. That line provides the cheaper and almost-as-fast option to Central London and beyond, using the same tracks as the Heathrow Express but also stopping at some intermediate stations.

Unfortunately, Heathrow Airport have very good signage to the Heathrow Express, and abysmal signage to the Elizabeth Line. I assume this is intentional.

I'm thoroughly confused on what it costs. The airport supposedly adds a surcharge as they own the last bit of track, but I can't find an official website saying what this surcharge is. More than the tube, but significantly less than the Heathrow Express, anyway.

(Before the Elizabeth Line there were also non-"Express" trains running on the same tracks, but the service was less frequent. Not many people knew about it.)

[OJFord]

There's no airport-specific surcharge, it's just zone 6.

Which for the Piccadilly line happens to only contain Heathrow, and Elizabeth line only Heathrow & non-London. But it's not hidden/secret, there's a zone 7, and other lines have more in 6.

[n_plus_1_acc]

They posdibly mean this:

> Journeys to or from Heathrow Airport are priced at a premium due to using the rail tunnel between the airport and Hayes & Harlington. That stretch of line is not part of the Network Rail system but owned by Heathrow Airport Holdings, who charge TfL an additional fee for each train that uses it. Heathrow is nevertheless included within the Travelcard scheme and daily/weekly fare capping as a fare zone 6 station.[80] https://en.m.wikipedia.org/wiki/Elizabeth_line

[n_plus_1_acc]

They are possibly referring to this:

>Journeys to or from Heathrow Airport are priced at a premium due to using the rail tunnel between the airport and Hayes & Harlington. That stretch of line is not part of the Network Rail system but owned by Heathrow Airport Holdings, who charge TfL an additional fee for each train that uses it. Heathrow is nevertheless included within the Travelcard scheme and daily/weekly fare capping as a fare zone 6 station.

https://en.m.wikipedia.org/wiki/Elizabeth_line

[Symbiote]

I have now found it on [1]. Yesterday this was showing £5.60 for both options, but now it shows £13.30 for the Elizabeth Line.

I think it's most likely TfL's annoying language/translation plugin (I'm not in Britain now) was messing something up, and the fare wasn't updating.

[1] https://tfl.gov.uk/fares/find-fares/tube-and-rail-fares/sing...