Transportation & Itinerary thoughts for Geneva - Montreaux - Lavaux - Lausanne - Geneva

Timetables at www.sbb.ch/en.

You will benefit by buying a Canton Vaud Mobilis Day Pass. the all-zone (which you will need) is 55.60 CHF per person. That sounds like a lot, but a round trip from Geneva to Chateau Chillon is over 80 CHF per person. You should receive a Guest card for your hotel that gives you free transport in Geneva, which you can use on your arrival day and to get you to the border of Vaud, just north of Geneva.

https://www.mobilis-vaud.ch/fr/tarifs/?type=Dailypass
https://www.geneve.com/en/already-here/geneva-transport-card-for-guests

You don't say where you are picking up the car, but presumably that's at the Geneva airport, on the French side, since you mention the car rental is for your drive to Annecy. I got advice on this forum a couple of years ago when my circumstances were similar to yours.

On the day I was asking about, we were going to be leaving our rental home in Murren very early in the morning and traveling by train to Montreaux. We wanted to spend that afternoon seeing and doing things in/near Montreaux, by public transportation, and then we'd take the train to Geneva's airport, as we needed to pick up our rental car, on the French side, by 8 p.m. That rental car booking was because we were driving to Chamonix.

I asked, on this forum, if it made more sense to arrange to pick up our rental car early that day. We'd travel from Murren to the Geneva airport to get the car, then drive to Montreaux. I figured that we would then be more in control of our time, seeing and doing all the things we wanted to see and do in the Montreaux area without worrying about a deadline to be at the airport to get the car. I knew that our rental car company permitted its cars to be driven in both France and Switzerland, regardless of which side of the airport rented from, with no extra rental fees (although cars not returned in the same country where rented would incur a high additional fee). I also knew that if you are driving a car on any "motorways" in Switzerland, you need to buy a 40 CHF vignette. This vignette isn't required using the car on Switzerland's "ordinary roads" and I wondered if I'd be driving on motorways or "ordinary roads."

A seasoned traveler on this forum advised that to drive to Montreaux from the Geneva airport would require this vignette because the straightforward route is the A1 autoroute to the A9 autoroute (vignette required for each). If we wanted to avoid the autoroutes we could take the lakeside road all the way and not pay for the vignette, but we'd need to be careful because at various points along the road, we might be guided onto a short stretch of road requiring a vignette. To avoid these stretches requires planning and adds 45 minutes to an hour to the drive, I was told.

It all sounded too complicated and we ended up sticking with our plan, using public transport in Montreaux, and not getting our car until the end of that day. I had in mind that while we were in Montreaux, we'd have lunch, then take a boat ride to Chateau de Chillon and tour the castle, then perhaps take a hike on some of the terraced wine trails near Vevey. We didn't have time for the latter. I'd underestimated how much time it would require to have lunch and visit the castle.

Based on my experience, I do think that what you've got in mind is too much for one day.

You could pick up a car on the Swiss side, then a Swiss vignette would already be on the car. Quickest way to Annecy from the airport is through Geneva, so you need a vignette anyway.