Drive or train in Switzerland?

If it's just the two of you then take the train. It's convenient and easy. The only reason to drive there is if you want to really explore off the beaten path or you have a large party or you're packing heavy.

We only did trans/transit in Switzerland and could get everywhere we wanted including the mountains. You may want to look into the parking situation. I didn't see (didn't look) what the parking situation is in cities, but cities like Luzern and Dovos-Klosters are very walkable and we had a free transit cards for local transportation.

https://www.car-parking.eu/switzerland/lucerne

Parking in Lucerne ​ The inner city of Lucerne is a pedestrian zone
where traffic is forbidden. Outside this area there are just a few
parking bays on-street. For a long stay we would like to advise to
park in the city centre car parks or in one of the P+R's on the
outskirts of the city.

https://www.car-parking.eu/switzerland/zurich

Parking in Zurich Parking on-street is hardly possible. Parking
spaces is the city centre are preliminary for residents with permits
and the maximum parking duration is limited.

And if you want to go to Zermatt:
https://www.zermatt.ch/en/arrival/Arrival-by-car

Zermatt is car-free. Access by private car is only permitted to Täsch.
From Täsch, one continues to Zermatt by train. Or by taxi or limousine
service as an alternative.

Täsch is 5 km from Zermatt. The road from Täsch to Zermatt is closed
for public traffic. The Matterhorn Terminal in Täsch has 2,100 covered
parking spaces. In addition, there are over 1,000 parking spaces
offered by private parties, such as taxi companies, hotels, etc. It
means one has to board the train in Täsch. An extensive taxi service
from different private companies also serves guests, who prefer to
travel to Zermatt by taxi.

Definitely train. Car rental rates are very high and parking is hard to find. It rains a lot in Switzerland, so even if you drive in summer/early fall (when there is no snow yet), windy hilly roads can be very challenging.

Actually, the train + bus system can bring you to many off-the-beaten path destinations too. The swiss govt really discourages driving to ease congestion.

Switzerland has the most efficient public transportation system in Europe and can get you anywhere throughout the country. Trains and cable cars are the best way to navigate the swiss towns.

Thanks for the input everyone. The airbnb's we are looking at all included parking. I did expect parking would be difficult. I am still interested in hearing how challenging the drive in the Alps would be, if anyone has experience.

If you head for the high peaks of The Bernese Oberland , be aware that there is no auto access on either side of the valley ( Murren , Wengen , Schilthorn , Jungfrau , et al ) . You will need to leave your car in the parking structure behind the bahnhof in Lauterbrunnen .

Regarding how challenging - I don't know what you or your husband are comparing it to.

Is he experienced in mountain driving - where you go down in the same gear you would have gone up in, and rest the brakes, and cool the brakes before they overheat, prepare for the hairpins before you get there, use the corner mirrors put up to see around the corner ? If so, no different than high mountain driving in Spain, Austria, or Italy. Much higher and steeper than Wales or Scotland in the mountain passes, but the road up to Lauterbrunnen is straightforward. Zermatt car park not quite so easy.

The road between Luzern and Meiringen, on the way to Interlaken and up, is single lane each way, with no passing. It just has one high pass, and one set of hairpins, with one double corkscrew. Once down on the approach to Meiringen it is autobahn to Interlaken.

He will need to be aware of the speed limits, and particularly around tunnels - the Swiss are extremely picky about tunnel safety and speeds are reduced a lot into and through tunnels. It is important to be going the - often 80 kph, but it varies - speed before the tunnel mouth. Many tunnels have cameras just at the entrance and inside.

Is this your personal car being driven from the UK?

Thanks Nigel, that's the info I was looking for! It would be a rental car we'd have. I'll show him your response and she what he thinks.

The train and transportation system in Switzerland is among the best in the world, so my suggestion would be to use well planned trips by public transit. As mentioned in a previous reply, some of the mountain towns are not accessible by car, so it would be parked, gathering dust and parking charges. You'd be using public transit to reach those mountain towns anyway.

Zurich, Lucerne, Lauterbrunnen, Murren - there is absolutely no need for a car. You can't even GET to Murren in a car. Do you think you will see the sights of Zurich and Lucerne by driving around the city from site to site, parking and then getting out to see the particular site. No way! That's not how it works in the cities. Sounds like you're just interested in driving in the alps. If that's the case then pick up a rental car when you leave Lucerne and drive till you've satisfied your driving desires.

But the easiest, most relaxing and most pleasant journey will be via train.