Except that if you are departing from CDG, you already need to know you are departing from Terminal 3 even before you get your gate assignment. At that point the separation of landside/airside concept is a benefit:you simply go to Terminal 3 because that's where you check in. And it doesn't matter if your flight departs from gate F14 or C89. Or if you get the gate assignment after you check in.

Conversely you will arrive in Terminal 6 for your flight and will not be surprised to see a gate 572 on your departure, pehaps going to Terminal 5 (because it's "logical") and being confused why you can't check in there. Instead you proceed to Terminal 6 and then to gates C. Also of note current T2B/D, future T4 which is causing also nowadays confusion, instead you have T4 common landside area and then you go to gates G or H depending on whether you are intra-Schengen or not. And you are guaranteed that the pax are in the correct concourse, and not hoping they are not on the wrong side because gates 401-422 are Schengen and 451-472 non-Schengen and how to explain if the gate is not assigned yet to the checking in passenger on where to go. (Not to mention the benefit if ADP finally decides to join the 21st century and converts one or two of the satellites to three-level S/NS combined operations)

Also you can't possibly mean seriously the suggestion that having lettered concourses is too confusing, but chucking terminals 7, 8 and 9 into one hall would not be.

Because the signage can then direct you to the F gates, noting also that you are being directed to terminal whereever-F-gates-are.

This is very important because good signage is paramount to an airport's success in performing its primary function: getting people onto planes. Having gates lettered F1, F2, etc lets you put up a sign that goes "F Gates -> (that way)" with a giant F. Using hundreds means people have to do math. Simple math, granted, but it's more mental work than just going "my gate starts with F and there's a big F there saying it's that way". Keeping this stuff as simple as possible is extremely important. Not everyone has the same reading skills.

No, ADP (and perhaps AF) is starting from a situation where they have to fit their numbering scheme into an international system that does not necessarily permit any random thing. Both from a technical standpoint and from an airport user standpoint (i.e., make it easy for the travelling public, not all of whom spend more time at the airport than at home.)
Not a single gate on the planet is called "3.14" or "T3G14". The only acceptable options are a single number (i.e., gate 1, 12, 123) or a letter and a number (F1, G12). The terminal is marked separately.

No this brings the same problem that exists currently: "where do I have to go to check in for my flight departing from terminal 9? Oh, terminal 7? What?" Terminals are understood by the general public to be separate entities. You cannot break that assumption or people will get confused. Such as how people get confused when AF makes people departing on some flights from T2E, check in at T2F. (So ideally they would also stop that nonsense.)

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I do think it makes very little sense for them to change the letters that already exist though. Why are the letters for terminal 5 not just K, L and M like they already are while it is still called 2E? And F for T6? Are they afraid they'll run out of letters? Saves you from having to put up new gate signs at *every single gate*.

Because then passengers would need to know which terminal their onwards flight departs from, which adds complexity as they need to research additional information. Why make it so complicated when you can simply tell them to go to "gate D34", instead of "terminal 6, gate 634"?

And good luck not confusing the hell out of people who check-in in one "terminal" but their gate is in another (as is the case at CDG for some AF flights).

The numbers and letters I used were an example of why this model is better than pure numbers. They don't reflect actual numbers used at CDG (which may or may not have been more logical, I don't care, I will follow the signs like I always did and like most pax do).

As an occasional victim of flights that say both 2F and an L gate on the app, I'm not sure the future is any clearer with telling people to check in at Terminal 6 for a flight departing from Terminal 5 hall C.

Well, that's the idea - terminal information is relevant for check-in only, then you just follow the signs for your gate (C gates in this example). Average passenger won't be concerned that this is designated as a different terminal.

In the articles talking about this change, ADP calls this a "choc de simplification" . This is really laughable as I don't see the simplification at all. If they wanted a simplification, instead of calling terminals 1 to 7 with letters for gate numbers, they should rather name the terminals with letters and use this same letter for gate numbering. I mean Terminal A (gates A1, A2, etc) to G (gates G1, G2, etc).

This remind me of my CDG-ATL a while ago. Purser announced correctly in French that we’ll arrive at Terminal I, while in English she pronounced that letter in French sounding like E in the English language. Before landing, the guy behind me was confused by the Mobile Passport Control app if he should mark Terminal E or F, while AF shows as arriving at I. FA had no clue so I turned around and told him AF will always use F. After landing, he muttered something about the FA announcing E…

For those who aren’t familiar with my home base:
ATL has “Terminal I” which refers to the landside area of the building that is physically Concourse F. All intl carriers use F for arrivals, which is where immigration and all formalities happen for all pax. With DL, you might park at Concourse E or F. If arriving at E, transit pax complete all formalities in E while ATL bound pax follow signs and take a long walk to F.

Except that the whole crux of the issue is that landside terminal areas do not correspond to gate concourses

leaving aside T1 and T3 (current), T2B and D are already combined landside, not corresponding to airside gates; and why would they, check in for easyJet is check in for easyJet regardless if you are flying to Ajaccio or Aberdeen, it's much simpler to have the checkin in one checkin row in future T4 regardless that gates will be D and B (future G/H).
Conversely for a flight departing from (current) L gates, check in can happen in T2F or T2E, arguably in T2F it's operationally simpler! As soon as you disabuse yourself from the notion "but but but L concourse is part of T2E!" you will realize that (future) T6 is even better connected to (future) C concourse because of the walkway than (future) T5.
(again, also making things easier if ADP decides ever to enter 21st century and build a Schengen level in at least satellite S3)

Very many passengers don’t start at cdg but connect there.

in terms of numbers and letters for gates which many of you seem to prefer, I’d be curious to know how frequent are multi terminal airports that use a mix of numbers and letters for all their gates.

in my experience, it is frequent for single terminal airports to use letters (eg DOH, IST, AMS, BRU, etc) to distinguish gates in various areas of the single terminal, but by contrast most multi terminal airports seem to use numbers only (most US airports, most British airports etc) except within a specific terminal which is sub divided (so for instance LHR uses numbers only, but if you use T5 you will get letters there only as T5 has three concourses).

happy to hear if my observation is mistaken but if not, are people so certain that everyone else is abysmally wrong and the new cdg plan is the only logical one?

One article mentioned 30% of business at CDG being transfer passengers. �Many�, but not �most�.

Then again, not sure how much to trust the media on this, i�ve also read higher numbers (>70%) in other places.

Thanks. I had heard "most" from my AF contacts but it may also be about AF specifically so in doubt I have rephrased into "very many". To be honest, I think that whether many or most doesn't really affect the points that worry me about what ADP are proposing to do so very happy to go for the conservative phrasing.

Your observations are clearly not mistaken, but there are two things to keep in mind imo:

First, a lot of these airports have existed for a very long time and perhaps a choice was made in the past that they would not make today, but making a change is hard. ADP deciding to change the mess that is CDG T2 took literal decades.

Second, I think most of the time airports that have separate terminals (without lettered gates) don't see a lot of passenger flow between terminals. Or at least, not if they aren't doing things like self-connecting. If you arrive at JFK T4 on a connection you're probably also leaving from T4. So it becomes less important to distinguish between "gate 4" at one terminal vs another. On the other hand, T2E at CDG has a huge interconnection area: 2E, 2F and 2G. It is so important that they highlighted it in the map.

Again the primary purpose of an airport is to get people onto planes. And wayfinding is a very big part of that, so having clear gate numbers that uniquely identify one place to be and to make it as simple as possible for a passenger to be told how to get there is of vital importance. I believe letter-number gates are the most elegant solution.

ATL is multiterminal (although not by much) and uses letters. JFK uses a mix of everything (numbers only within terminal, 5xx numbers in T5, A/B concourse in T4...) ORD is multiterminal and uses lettered piers so does SFO.
In Europe, FRA does A-H+Z across it's 3 terminals (T3 being planned to open Q2 26 and already signposted), MUC A-L across 2 terminals, PRG has A-D across 2 terminals (T3 being a numbered terminal not used for commercial traffic)
In Asia, I have already mentioned SIN, A-G across 4 terminals, and I'm pretty sure same will be the case in multi-pier T5. PEK uses numbers only for T2, but lettered piers in T1 and T3.

It really isn't rare, at all.

Both can be true at the same time, in a way - a majority of total number are O&D, but majority of AF pax specifically are connecting.

O&D pax are a little different because they are expected to go through landside, but there is still the issue of (new numbering) T4 G/H gates and T5/6 for C gates, whatever way you cut it.

I hear they are re-introducing the Republican calendar to dovetail with the new Terminal names .....in order to simplify things.

Sorry, but... what was wrong with the current numbering (other than checking in at 2F for 2E departure)?