Three weeks-help!

If he is on a budget, spend more time in Czech Republic, Poland, Hungary, Slovenia.

Agree with Sam, most of the places on your son's wish list, like Paris or Switzerland, will be some the more expensive places to be in Europe. If I was a student on a budget, after Prague, I would consider venturing east to through Czechia, Poland, maybe the Baltics. If it's the summer studying abroad then by all means stay north of the Alps.

You sound concerned. Don't be. He will be with other students in this program and they will use their collective consciousness to make plans. Obviously, he will determine what he wants, and what he can afford. If he is as I was when I was first traveling solo in Europe, he will ask lots of people for ideas when he gets there, and will change his mind several/many times. Three weeks is either plenty of time to hit 5-6 cities if that is all he wants (Vienna [10 hrs by train to] -Milan [3.5hrs by train to] - Lucerne [5 hrs by train to] - Paris [2hrs by train to] - Brussels), and not nearly enough time to really appreciate each of them fully.

He may get invitations to places/couch surfing(?). He will end up staying in a lot of hostels in some smaller/stranger places. He may decide to take Swiss Post buses like I did and end up in some gorgeous small places. Great!

I suggest you buy him e-copies of the relevant RS Guidebooks ~$100 total to load on his tablet and let him figure it out as he goes. The guidebooks have many, many useful weblinks to help in his planning, and budget friendly housing suggestions.

And there is always Deutsche Bahn for general point to point train reference.
https://www.bahn.de/en/view/index.shtml

That's a lot of places, but he will figure it out. I wouldn't advise it, too rushed for me, but I assume he is college age and probably has plenty of energy.

One thing to remember is that in most study programs weekends are free, and some have Friday off as well, or at least finish early on Friday. It is certainly possible he will make friends in the program and take weekend trips to some of these places, therefore will not have to fit them into his 3 weeks at the end. Depending on where he is in Germany, some of his wish-list places may be an easy train or cheap flight away.

As to your idea of the romantic road...if that's his interest, great. However, he will have just spent 3 weeks in Germany and may want to use that time to see other countries. The most logical route depends on 2 things - where in Germany he is, and where in Switzerland he wants to go (the other places are cities, Switzerland is obviously a whole country so he will need to pick one base area and see what is near it.)

In general, I'd start by looking at this order - Prague - Vienna - Milan - Switzerland - Paris - Brussels. Just geographically makes the most sense. Definitely Paris last before Brussels - these 2 are easily connected by train.

Has he got a railpass or will he be buying tickets as he goes?

I bet he will have a great time!!

Are we making valid assumptions about his age or is this a special high school class?

That route is fine for 3 weeks. He won't have too much time in these cities, but he's young and let's hope that this will be only his 1st trip to Europe, but not his last. He'll have a first impression of these cities.

Trains are pretty fast in these countries, for example Paris to Brussels is about 2 hours, Prague - Vienna 4 hours, so even on some travel days he'll have at least half a day left for sightseeing. On longer routes(Vienna - Milan) he could take a night train to see what it is like and either swear never again(it'll be still a good story to tell later) or get hooked and be part of the small, but enthusiastic community of travellers who love night trains. Finally I hope he'll discover what way too many travellers don't realise, that time spent in transit is not necessarily wasting your time, but the journey itself can be an integral part of your travel experience. Talking from my own experience: Spending a whole day on trains travelling across Switzerland was a better experience(and revealed more about the country) than a whole day spent in Zürich or Bern.

https://www.seat61.com/Railpass-and-Eurail-pass-guide.htm#Why explore Europe

"He is on a limited budget and is concerned about the cost of Switzerland."

It would be more helpful to specify his actual budget than say it is limited. $100/day is a limited budget for many travellers, a luxury for others, $50/day is also a limited budget, but way more limited than 100.

I travelled many times to Switzerland(one of my favourite countries) on a relatively low budget(that's what I can afford) and always found Switzerland expensive, but generally great value and money well spent. Many great things are free or not more expensive than elsewhere in Europe and with a little creativity you can find many ways to save money.

Cindy, I think it's nice your wanting to get some suggestions for your son's travel before he sets out. As a Mom, of course you would be a bit worried and caring. No matter how old he is, he is still your son. When we are college age or thereabouts, it seems we feel like we can conquer the World, lol. Then, reality takes a front seat.

Researching and planning ahead will set him in the right direction with maybe some wiggle room.

As an aside, take considerations with how he will store his money (money belt as an example), his bank card/credit card - usages, fees (if any), withdrawal limits < fees, exchange rates, monies from each < look on the net for pictures of foreign currency and denominations.

All the countries/cities he would like to visit seem to be on the more expensive end. With some proper planning, he may be able to enjoy some time in each.

He is on a limited budget and is concerned about the cost of Switzerland. https://www.myswissalps.com/swissfranc

Here is a link to browse for some beginner ideas: https://www.nomadicmatt.com/travel-blogs/backpack-switzerland-on-a-budget/ Sometimes, travel passes are not cost effective.

For Milan, some things to read https://www.rome2rio.com/s/Milan

He needs to be very mindful of putting anything of great value in a back pack - money, cards, PP, phone, Ipad, etc. I presume he'll backpack it. So, he needs a good "lock" on the zippers while in crowds or on the train/bus. Just keep a big city awareness.

Oh, and if he drinks beer, of course he should know to not indulge; especially as a solo. It's unfortunate, but some wolves in the World prey on young kids or take advantage of those who may be happy go lucky, a little innocent or eager.

From the answers, it seems not all have the same interpretation of what a 'three week extension' is. Is this a group planned travel, or is it just him planning to personally extend his time in Europe? I assume it is a personal trip, as you are recommending changes). Clarity would make it easier to reply.
For young travelers, I recommend Lonely Planet 'Europe on a ShoeString' to deal with Switzerland and all other countries.
I honestly don't think this plan is that onerous for 3 weeks. Sure there is logic to try and group a region together, but there may be some cheap flights from Vienna to Milan making it feasible.
There is a couple of cool train routes from Milan or the Italian Lakes to Switzerland which would be a great opportunity.
A quick check shows Zurich hostels are more expensive than say, Berlin hostels,(about $25 more a night) but he doesn't have to stay long in Switzerland and may have better luck in smaller towns.

If you take into consideration that every move is 1/2 a day, that's 2.5 days out of 21. Considering some of the expectations of families traveling for just 2 weeks, your son't plan isn't so bad.

Cindy, where is he going to be in Germany? I think the likelihood of getting different ideas and travel companions is pretty high, and that would change plans. So I'd concentrate on the flexibility and how to get around etc., rather than the specific destinations. The Lets Go: Europe series of travel books was written for the budget college traveler.

You might be mixing up two different things: the Romantic Road (in Bavaria) and the Black Forest further west. Both great areas to visit, but not something a young man might find as interesting.

His first three weeks will be a program based in Berlin. After that he is on his own. He is extremely busy with school/work and had asked for my help in planning. Thank you for the many replies. You were all very helpful and the information helped him out a ton with his planning.

Hi Cindy,

That's great some preliminary suggestions/thoughts for your son steering him in the right direction for further research and planning. Family and friends help without judgement. I'm very grateful for the help I've received over the years from family and friends. No matter how old we get, it's a nice feeling to have family care, be available to get their advice or learn from their wisdom.

Sure, we eventually need to spread our wings and make our own flight path...but it's wonderful to "come home" too.

Best to your son and his travels!