How to get from Vienna Hauptbahnhof to Südtirol Plaza

Confusing question. Südtiroler Platz is right outside the Wien Hbf.

I was there last October and there was a lot of construction going on on the roads around the train station. It was confusing. But I wouldn't worry about it, once you get to the train station, google maps will give you several easy options to get to from the train station to Stephansplatz.

So don't worry.

Sudtiroler Platz and Hauptbahnhof are the same place.

I also think you mean the U1 as the U2 does not stop at Hauptbahnhof/Sudtiroler Platz and does not go towards Leopoldau nor does it stop at Stephansplatz.

When you get off at Hauptbahnhof, just follow the signs to the U1 - there is an underground passage. I walk there every day. It is well signed. You absolutely do not walk on a highway! Also the U3 option would take longer and is more difficult to navigate.

Thank you. thank you. I had wondered if the Google maps trail was actually taking me to an underground passage that went UNDER the highway, but there was no way I could tell there. I was down to "well, I guess we'll figure it out when we get there," and I'm grateful we won't have to do that after a seven- or eight-hour train ride. Many thanks.

What is your exact destination in Vienna?

I had wondered if the Google maps trail was actually taking me to an
underground passage that went UNDER the highway, but there was no way
I could tell there.

My experience with Google maps is that for walking routes it ranges from semi-decent to useless.

I agree about the advantages and disadvantages of Google maps for walking routes. For that matter, it can sometimes be weird for driving routes. I once had Google direct me OFF a main drag, through a random maze of back roads, and then back on to the same main drag several miles later. Best guess was that at the time they plotted it, there had been some kind of construction going on that wasn't going on anymore. The advantages, though, are that I can study the map, blow it up at will, and plot my own route (which I've done for our lodging in Zürich), and also go in with Mr. Peggett and take photos of key intersections to help me keep my bearings.

The best choice for finding your way in Vienna is this:
https://anachb.vor.at/webapp/index.html?language=en_GB

You enter a location/address for Start and Destination respectively (and optional date and time) and you will get route information for public transport, walking, cycling and going by car.

It is also available for as an app for smartphones.