Zermatt to Salzburg

I would take the train and break up the trip with an overnight stop in Switzerland, maybe a lake town such as Brienz. The train takes 9 to 11 hours or so,; it would be a long day to do it all at once. But flying isn't any better---as far as I can tell, the closest airport is Geneva, 4 hours by train from Zermatt. Lufthansa has flights from there to Salzburg, stopping in Frankfurt, but that takes another 5 hours. (Maybe there are other options; I didn't check). As for the car, one-way rentals in Europe generally incur a hefty drop charge; gas is very expensive, and Austria requires a special sticker (not sure how much it costs) to use the highways.

We always travel by train in Switzerland---it is pleasant, fast, and reliable. That's your best option, I think.

Agree with Lola. Take the train and enjoy the wonderful majestic scenery.

thanks for the tips. What about just driving back
to Zurich and flight to Salzburg?

Do you already have a car? It won't do you much good in Zermatt; you'll have to leave it in the parking lot at Tasch. I don't know how long it would take to drive from there to Zürich; I think Michelin or one of the sites will give you times and directions.

Zürich to Salzburg is 5 hours 49 minutes if you catch one of the several direct trains a day. The flight is only a little over an hour, but you have to build in extra time to get to the airport for security, checking bags, etc., and getting to and from the airport at each end. The nice thing about trains is you can show up 2 minutes before departure (assuming you already have a ticket), and it will take you city center to city center.