Multiple Routes To and From Switzerland Disrupted This Summer

The timings of when major work will be carried out on railways isn't co-ordinated across Europe, so it's a tad random that more 50% of the international express trains from and to Switzerland will be impacted at various times during summer 2024.
Railway engineers prefer to carry out large projects in the summer because of the good weather and longer daylight hours.

As will be seen below, the express train routes and services which will be impacted this summer are:

1. (Venice - Verona) - Milano - Stresa - Domodossola ↔ Brig - Visp - Sion - Lausanne - Geneve by EC trains
2. Milano - Stresa - Domodossola ↔ Brig - Visp - Spiez - Thun - Bern - Olten - Basel by EC trains
3. Multiple cities in Germany - Karlsruhe - Freiburg (Breisgau) ↔ Basel - Olten - Bern - Thun - Spiez - Interlaken by ICE trains
4. Multiple cities in Germany - Karlsruhe - Freiburg (Breisgau) ↔ Basel - Zurich - Chur by ICE trains
5. Paris - Dijon - Mulhouse ↔ Basel - Zurich by TGV Lyria trains
6. Paris - Frasne ↔ Vallorbe - Lausanne by TGV Lyria trains
7. Budapest / Bratislava - Vienna/Wien - Salzburg - Innsbruck - Feldkirch ↔ Buchs - Zurich by Railjet trains
8. Graz - Innsbruck - Feldkirch ↔ Buchs - Zurich by EC trains

The Milano ↔ Tirano route which provides connections to and from the Rhaetian (Rhb) Railway services, including the Bernina Express, will also be partially closed

Also these three services...

1. Milano - Como ↔ Chiasso - Lugano - Bellinzona - Arth-Goldau - Luzern - Olten - Basel by EC train
2. Milano - Como ↔ Chiasso - Lugano - Bellinzona - Arth-Goldau - Zurich - Basel - Freiburg (Breisgau) - Karlsruhe - Frankfurt (Main) by EC train
3. Genova - Milano - Como ↔ Chiasso - Lugano - Bellinzona - Arth-Goldau - Zurich by EC trains

...will be suspended until September 2nd due to the repair work being carried out in the Gotthard Base Tunnel.

The express train routes and services which won't be impacted by construction work, are;

1. (Venice - Verona) - Milano - Como - ↔ Chiasso - Lugano - Bellinzona - Arth-Goldau - Zurich by EC trains - though except on Saturdays, the journey time will be an hour longer until Sept 2nd, due to the repair work in the Gotthard Base Tunnel.
2. München / Munich - Lindau ↔ St Gallen - Zurich by ECE trains
3. Stuttgart - Singen ↔ Schaffhausen - Zurich by ICE trains
4. Friedrichshafen - Singen ↔ Schaffhausen - Basel by RE trains
5. Paris - Bellegarde ↔ Geneve by TGV Lyria trains; though from 29 June to 18 August, no journeys will be extended beyond Geneve to and from Lausanne.

The railway between Arona and Stresa is closed completely from June 9th to September 8th, so during these dates the following EC express train services to and from Switzerland will be turning around in Brig or Domodossola:

1. (Venice - Verona) - Milano - Stresa - Domodossola ↔ Brig - Visp - Sion - Lausanne - Geneve
2. Milano - Stresa - Domodossola ↔ Brig - Visp - Spiez - Thun - Bern - Olten - Basel

So the trains on these two routes won't be travelling to and from Milano.

Replacement buses will be operating between Milano Centrale station and Domodossola and as a consequence end-to-end journey times to / from Milano will typically be extended by more than two hours.
According to the Trenitalia booking service most journey options from June 9th to September 8th will involve taking;

1. Trains from/to Swiss locations usually served by the direct trains ↔ Brig
2. Local / regional trains from Brig ↔ Domodossola
3. Buses from Domodossola ↔ Milano Centrale station

Note that because of these arrangements journeys between Switzerland and Milano are being displayed as unavailable on Omio, Trainline and RailEurope.

The alternative to travelling via Brig and Domodossola is to take trains to/from Zurich in order to connect in and out of the Zurich ↔ Milano Centrale trains.
Though separate ticket bookings per train will be required for travel via Zurich.

Due to the partial closure of the Hauenstein Base Tunnel south of Basel, most of the TGV Lyria services between Basel SBB and Zurich will be cancelled from 7 July to 12 August 2024.
The only exceptions are the trains which depart Zurich at 06:59 and the train which departs Paris at 18:22.
All other services from and to Paris will be turned around in Basel, with connections required for travel between Basel SBB and Zurich HB stations.

Then from 13 August to 14 December 2024 the service won't be restored to the usual pattern because construction work north of Dijon, will result in the Paris ↔ Basel - Zurich service being reduced from six to four departures per day.
According to the Lyria journey planner, one of these trains, the 10:52 departure, will be diverted on to a longer route via Strasbourg - so will have its journey time extended by around 1hr 20mins.

Due to works in Switzerland from 29 June to 18 August 2024 the trains on the Paris - Geneve ↔ Lausanne route will be turned around in Geneve.

Also construction work in France will result in Monday to Friday services on the Paris - Frasne ↔ Vallorbe - Lausanne route being reduced from three to two x trains per day from August 13th to December 13th.
The cancelled services are:

1: Paris to Lausanne train (9269) departing at 11.56 (except Sept 9th and November 11th and 12th)

2: Lausanne to Paris train (9268) departing at 12.23 (except Sept 9th).

From July 16th, until the pan-European timetable refresh on December 15th, the route in Germany between both Frankfurt (Main) Hbf / Frankfurt Flughafen and Manheim is closed for maintenance works.
As a consequence the following alterations between to the usual service will be in operation between these dates.

(Interlaken) - Basel ↔ Braunschweig - Berlin

Usual route:
(Interlaken - Bern) - Basel - Freiburg(Breisgau) - Offenburg - Karlsruhe - Mannheim Hbf ↔ Frankfurt(Main) Hbf - Fulda - Erfurt - Kassel - Braunschweig - Wolfsburg - Berlin

July 16th to December 14th:
(Interlaken - Bern) - Basel - Freiburg(Breisgau) - Offenburg - Karlsruhe - Mannheim Hbf ↔ Frankfurt(Main) Hbf - Fulda - Erfurt - Kassel - Hannover - Hamburg
Though when similar alterations were made in 2023, most of the services were turned around in Basel SBB station.

Zurich - Basel ↔ Hannover - Hamburg

Usual route:
(Chur) - Zurich - Basel - Freiburg(Breisgau) - Baden-Baden - Karlsruhe - Mannheim Hbf ↔ Frankfurt(Main) Hbf - Fulda - Erfurt - Kassel - - Hannover - Hamburg

July 16th to December 14th:
(Chur) - Zurich - Basel - Freiburg(Breisgau) - Baden-Baden - Karlsruhe - Mannheim Hbf ↔ Frankfurt(Main) Hbf - Frankfurt(Main) Hbf - Fulda - Erfurt - Leipzig - Halle(Saale) - Berlin
Though when similar alterations were made in 2023, most of the services were turned around in Basel SBB station.

Basel ↔ Köln - Hamburg

Usual route:
Basel - Freiburg(Breisgau) - Offenburg - Karlsruhe - Mannheim Hbf ↔ Frankfurt Flughafen Fernbf - Siegburg/Bonn - Köln Hbf - Dortmund - Bremen - Hamburg

July 16th to August 9th:
Basel - Freiburg(Breisgau) - Offenburg - Karlsruhe - Mannheim Hbf ↔ Mainz - Koblenz - Bonn - Köln Hbf - Dortmund - Bremen - Hamburg

August 10th to December 14th:
Basel - Freiburg(Breisgau) - Offenburg - Karlsruhe - Mannheim Hbf ↔ Weisbaden - Köln Hbf

As a consequence Frankfurt Flughafen / Airport will temporarily be deprived of direct rail links with Basel.

Basel ↔ Köln - Amsterdam

From July 15th the daily ICE train which takes a Basel - Freiburg(Breisgau) - Offenburg - Karlsruhe - Mannheim Hbf ↔ Frankfurt Flughafen Fernbf - Siegburg/Bonn - Köln Hbf - Arnhem - Utrecht - Amsterdam route is to be permanently withdrawn.
It can't resume from the December 15th timetable change due to scheduled works on the line between Duisburg and Arnhem.

Between these dates railway between Karlsruhe and Baden Baden will be closed, hence trains will be turned around in Karlsruhe, with an hourly shuttle service of ICE trains on a Basel - Freiburg(Breisgau) - Offenburg - Baden Baden route.
Buses will connect Karlsruhe with Baden Baden.

When travelling to and from Zurich during these dates, the alternative route will be travelling to and from Stuttgart to connect into the Stuttgart ↔ Zurich trains.

Due to construction work some long-distance trains will be diverted via St.Margrethen between Buchs SG and Sargans from August 10th, 2024 to September 9th, 2024 so journey times will be extended, though details have yet to be confirmed.

This is the route taken by the daytime Railjet trains on the Zurich ↔ Innsbruck - Salzburg - Wien - Budapest / Bratislava route and the EC trains on the Graz - Innsbruck - Feldkirch ↔ Buchs - Zurich
Though despite the fact that trains are seemingly being diverted and not cancelled, a replacement rail service with buses is to be set up - though it seems that this will be in place because the Railjet trains are not calling at Sargans between these dates.
The night trains are also being rerouted.

The timetable between June 9th and Sept 8th is awaiting confirmation.
But it very much looks as though, during this time, a section of the railway will be closed west of Tirano, with a bus substitution in place for part of the journey.
This train service is operated by Trenord, so presumably details will soon be confirmed on its news page.
This will extend journey times by 20 to 30 minutes, which will impact on connections with some Rhaetian Railway services in Tirano.