no problem. For such edits, for instance inserting a bridge to an existing highway, use the SPLIT tool in JOSM:
1. Add nodes at the exact start and end points of the future bridge on the highway way (use the Add Node tool or double-click with the Select tool).
2. Split the way twice:
Select the highway way.
Use the Split Way tool (shortcut P) on the two new nodes.
→ JOSM will automatically replace the old way in all relations (including the bus route) with the appropriate new segment(s). It usually preserves order correctly.

3. Select the middle (bridge) segment and add the tags:
bridge=yes
layer=1 (or higher if needed)
Other relevant tags (e.g. bridge:name=*, maxweight=*, etc.)

Check the relation:
Open the Relations panel (button on the left).
Select the bus relation and verify the members.
The original way should now be replaced by the three segments (before + bridge + after), all still in the relation.

Hello, thank you for adding details to openstreetmap! With this edit you broke 54 bus relations. I am fixing them for now. please pay more attention to relations during your edits.

fixed

Bus lines rerouted

Hello, thank you for map improvements. Next time please make sure you dont break bus relations that runs through the area. I am fixing it for now.

I am fixing it for now. Next time please make sure you dont break bus line relations that runs through the edited intersections, thank you

Thanks for the feedback and for checking the routes around Geneva. Improvements are always welcome.
1. Yes, by “most logical” I mean the route that makes the most sense on OSM (main roads, sensible turns, etc.). There are occasional ways to see the actual Flixbus route via their tracker, but I don’t systematically cross-check existing relations with it. When I notice a gap in a relation, in 99 % of cases it’s obvious how to fix it. The remaining 1 % I handle case by case.
2. When you select a city on a Flixbus line and are lucky enough that a bus is currently running, you can track it here: https://www.flixbus.de/track. Again, this is all manual work — no automation.
3. You’re right, the data shown on the tracker isn’t perfect. Unfortunately I’m not aware of a better public source. In the end, local knowledge remains the best reference.
4. Yes, that’s possible.
5. Yes, also possible. When I have time I plan to focus a bit on Bratislava as well.
6. A standard note/disclaimer sounds like a good idea. I wouldn’t do a bulk update of all Flixbus relations right now (there are hundreds of them, and many other bus networks in OSM have similar data quality issues), but I’m happy to add it when I edit individual relations. Feel free to draft a proposed wording and we can refine it together.
7. As you know, the Czech Republic is my home country, so most of my local knowledge naturally goes into improving local bus connections.

thank you!

thank you, fixed now.

is this really one-way road?

Hello,
thank you for the reminder.
Objective and limitations: My routine aims to keep existing Flixbus route relations in OSM functional by repairing them when they break due to other edits, road closures, one-way changes, construction, etc. The main goal is to maintain connectivity for routing and public transport analysis.
Limitations: I only repair existing relations — I do not add new Flixbus lines or remove obsolete ones, as there is no reliable centralized timetable.
Countries covered: The edits cover all countries where Flixbus relations currently exist in OSM (essentially all countries Flixbus operates in within Europe).
Route coverage: I work on all existing Flixbus relations in OSM. I do not verify whether individual routes are currently in service. Inactive or suspended routes remain in OSM unless removed by other editors. There is no systematic removal of outdated relations on my side.
Significance of ways: The ways included in the relations represent the actual (or most logical) route the bus takes on public roads. When multiple reasonable options exist, I generally choose the one that best matches the official Flixbus route (when known) or the most commonly used path. It is not random.
Alternative modeling: I have not seriously considered alternative modeling approaches (e.g. only using stops without full way members), because the current OSM practice for long-distance bus routes is to include the ways. Changing this modeling approach would be a larger community discussion.
Types of checks: I primarily check for and fix:

Broken relations (missing or invalid way members)
One-way road conflicts
Construction zones (highway=construction)
Occasionally reroute to the second carriageway on dual carriageways (especially in Poland)
Support from Flixbus: There is no support, cooperation, or contact with Flixbus. This is a purely voluntary community effort.
Data verification: I do not have a systematic method to cross-check against the official Flixbus timetable. I sometimes use https://www.flixbus.de/track for individual routes, but this is done manually and only selectively. I mainly rely on the PTNA Flixbus analysis tool (https://ptna.openstreetmap.de/results/EU/EU-Flixbus-Analysis.diff.html).
Timing and sources: My routine is fully manual, so I perform it as my time permits. I use PTNA analysis as a main source of information, and Geofabrik (https://tools.geofabrik.de/osmi/?view=pubtrans_routes) as a visual check.
I have not considered my activity important or systematic enough to warrant a dedicated page on the OSM wiki.

Hello,
thanks for the reminder.

My Flixbus edits are done manually, preferably every morning.  Main objective is to restore broken Flixbus lines relations, caused by other users' edits, closed roads, one-way roads etc.
My edit covers all countries operated by Flixbus - or, better say, all countries where Flixbus OSM relations are present.
 I dont verify if the lines are still active since there is no centralized Flixbus timetable, adding new or removing obsolete Flixbus lines is out of my scope.
Significance: Sometimes it is possible to verify bus route at https://www.flixbus.de/track, but not always. Since my edits are manual, I use that method for selected edits only.
I check broken relations and one-way roads mainly. In some countries (especially Poland), local editors reals being repaired as highway:construction. If my time permits, I re-route the bus relation to the second lane of dual carriageway, but not always.
 There is no support from Flixbus for my edits
I did not develop any script for cross-checking with other sources.
My routine is fully manual, so I perform it as my time permits. I use PTNA analysis https://ptna.openstreetmap.de/results/EU/EU-Flixbus-Analysis.diff.html as a main source of information, and Geofabrik https://tools.geofabrik.de/osmi/?view=pubtrans_routes as a visual check.
I didnt consider my activity as important, or systematic, that it would deserve an osm.wiki page.

Hello,
thank you for the reminder.
Objective and limitations: My routine aims to keep existing Flixbus route relations in OSM functional by repairing them when they break due to other edits, road closures, one-way changes, construction, etc. The main goal is to maintain connectivity for routing and public transport analysis.
Limitations: I only repair existing relations — I do not add new Flixbus lines or remove obsolete ones, as there is no reliable centralized timetable.
Countries covered: The edits cover all countries where Flixbus relations currently exist in OSM (essentially all countries Flixbus operates in within Europe).
Route coverage: I work on all existing Flixbus relations in OSM. I do not verify whether individual routes are currently in service. Inactive or suspended routes remain in OSM unless removed by other editors. There is no systematic removal of outdated relations on my side.
Significance of ways: The ways included in the relations represent the actual (or most logical) route the bus takes on public roads. When multiple reasonable options exist, I generally choose the one that best matches the official Flixbus route (when known) or the most commonly used path. It is not random.
Alternative modeling: I have not seriously considered alternative modeling approaches (e.g. only using stops without full way members), because the current OSM practice for long-distance bus routes is to include the ways. Changing this modeling approach would be a larger community discussion.
Types of checks: I primarily check for and fix:
--Broken relations (missing or invalid way members)
--One-way road conflicts
--Construction zones (highway=construction)
--Occasionally reroute to the second carriageway on dual carriageways (especially in Poland)
Support from Flixbus: There is no support, cooperation, or contact with Flixbus. This is a purely voluntary community effort.
Data verification: I do not have a systematic method to cross-check against the official Flixbus timetable. I sometimes use https://www.flixbus.de/track for individual routes, but this is done manually and only selectively. I mainly rely on the PTNA Flixbus analysis tool (https://ptna.openstreetmap.de/results/EU/EU-Flixbus-Analysis.diff.html).
Timing and sources: My routine is fully manual, so I perform it as my time permits. I use PTNA analysis as a main source of information, and Geofabrik (https://tools.geofabrik.de/osmi/?view=pubtrans_routes) as a visual check.

I have not considered my activity important or systematic enough to warrant a dedicated page on the OSM wiki.

Hallo, can you tell what is wrong with the route? Relation seems to be right with no issues. Please advise.

Čert vem "dej přednost", ale rozhodil jsi bus relace. Dal jsem to dohromady, ale příště prosím na to pamatovat, díky

"ale dalo by se to snadno zprovoznit" ¨myslím že neplatí, tomu zprovoznění předchází několikaměsíční rekonstrukce. Ale myslím, že sio rozumíme. Vrátil jsem Disused: a zároveň jsem stanici vyhodil z relace, to odpovídá nejvíc současnému stavu.

Zdravím, prefix disused: zase zlobí v relacích a checkery, napře. geofabrik to vyhodnotí jako chybu. Podle mého chápání je disused určeni pro prvky zrušené nebo zavřené na neurčito, např. výrobní haly, obchody apod. V tomto případě se jedná jen o rekonstrukci, i když delšího charakteru

sorry, fixed

sorry, fixed

Třída Osvobození v Příbrami je opravdu teď jednosměrná? Prosím o prověření, díky

Hello, thank you for checking. I was repairing the broken bus relation , did not find any note about diversion on the ZTM pages. I will put back the one way, not to spoil the map

Which elements?