One Full Day in Oslo--Guide or No Guide?

It depends a bit on what you want to accomplish and what limited walking mobility means. Of course you can pay someone to drive you around for half a day, but there are a few things to keep in mind. 1. It's Norway, paying someone to drive you around for half a day will not be cheap. 2. Many European cities are limiting cars, restricting them in many areas and outright banning them in other. And Oslo is one of the cities that have gone the furthest, so seeing the city by car is not the most efficient way.

Hoho buses can be helpful and if you just want to get an overview of the city it might be what you are looking for. Although a full loop takes 90 minutes and if you just have one day you'll have to consider if that is how you want to spend the time.

With a half day time between two flights I spent my time in Oslo by taking HoHo buses. For me it was OK - I had no specific interests for that time slot. Just wanted to have a general overview.

A tour guide would make sense to me if you have very specific interests in parts or special topics of Oslo.

In no case rent a car to explore Oslo. It is one of the most car-unfriendly cities I have been to.

Both of these comments are so helpful to understand how the city works in relation to being car-friendly. I'm thinking, then, that a guide wouldn't be as useful for helping cut down on the walking. They are, of course, useful in many other way! But for this particular day, maybe doing the HOHO would get us where we want to go with easy transportation between. I'll look at what all of their stops are. Thanks so much for the input!

One last thing: I decided to take the train to National Theater and take the HoHo from there. For me it was easy to find afer short orientation.

It depends on where you want to go. Hoho buses can be useful to get an overview of the city, but they are rubbish as a way to get around. But there is a great network of trams, buses and metro in Oslo.

@Badger, I get that perspective. But it seems the Oslo HOHO does have stops at the main places we would want to see. I'll do a bit more research on the other transportation options before I decide, though. Thanks!

You still haven't mentioned what the places you want to see are, so it's impossible to give specific advice.

But keep in mind that the Hoho-buses are not the only ones that have stops close to major attractions. And they don't take the shortest and fastest route. Also, they only run in one direction so if you want to go back, you have to take almost the full tour.

Sorry, I didn't realize anyone would care about those details. From the list I've made, I think the Norwegian Historical Museum (where the viking stuff is right now), Vigeland Park, and Norsk Folkemuseum (stave church) are our most important places to visit. Other places on my list are fine with a drive-by (Akershus Fortress, National Museum, Royal Palace, Norwegian Parliament). Would be nice to walk around Akershus Fortress but that will depend on my BIL's stamina. I'm trying to keep in mind the amount of walking required each place. Our hotel is near the Opera House so we will see that.

I did make a dinner reservation last night that is at a restaurant close to our hotel, so by that time of day we will be able to stick close.

Without knowing your BiL's limitations, consider what the Norse FolkMuseum says about accessibility. https://norskfolkemuseum.no/en/plan-your-visit

You probably have found that statement. Having visited just last summer, there is much walking required, including to the Stave Church. Other areas areas are also hilly.

Vigeland Park, although flat, is a large area. Depending on HOHO drop-off, a distance could be required to get close to the statues.
https://www.euansguide.com/venues/vigeland-park-oslo-8542/reviews/gustav-vigelands-legacy-7663

Not sure how much you would see with a drive-by to your other locations. Akershus Fortress and Royal Palace are on hills, the National Museum from the outside is not a special sight (in my mind). You can google image. The Opera House is more interesting architecturally in my opinion. That could be a drive-by.

We took a few taxis. I don't recommend. We had to negotiate and couldn't always find a driver who would agree to our destination.

We will be going to other stave churches, so maybe we should skip the FolkMuseum. I watched video yesterday that included Vigeland Park and saw how large it is. I'm thinking I'll have my sister and BIL look at the specifics of these places and decide what is doable for him. But also, this is why I'm trying to limit the amount of walking required just to get to these places.

I have heard the same thing about taxis so will try to avoid those unless really needed.

From the list I've made, I think the Norwegian Historical Museum
(where the viking stuff is right now), Vigeland Park, and Norsk
Folkemuseum (stave church) are our most important places to visit.

Those three are all very easy to visit on your own using trams and buses. And maybe a bit of metro. The Historical museum is located close to Nationaltheathret, a major transport interchange well served by public transportation. The Vigeland park is also easy to reach, Majorstuen metro station is close by, and if you want to save a bit of walking, two stops on the tram will take you to just outside the largest entrance. The Folk museum is a bit outside, but there is a bus stop just outside the main entrance and bus 30 takes you without any problem. Bus 30 runs every 10 minutes for most of the day, which is quite a lot better than the Hoho-bus that runs every 30 minutes.

Other places on my list are fine with a drive-by (Akershus Fortress,
National Museum, Royal Palace, Norwegian Parliament).

I agree that you really need to reconsider a "drive by" for those places. Akershus fortress is located on a hill and if driving by it or walking around it you will see stone walls and not much else. The interesting views are on the inside. And if you really want to see it from the outside, the views are better from Aker Brygge. The Parliament is charming and can be worth a stop to look at, but it would not be high priority for me.

The National museum is a great museum, but if you don't have time to visit the inside I really see no point in looking at it from the outside. It's not a very interesting building in my opinion. The Royal palace is also on a hill, but more important it is in the middle of a park. Planning a "drive by" to see the the Royal palace makes no sense. You can get some glimpses of the palace from the road, but if you really want to see it you have to walk.

The Opera house though is well worth seeing from the outside, and to walk up on it.

@Badger, thank you for this advice. I'll research those forms of transportation you mention for those locations.

We tend to walk when possible, so on our September day trip we walked from the train station Vigelandsparken and back with lots of tops along the way. I think the HOHOs are more fun than public transportation, so that would have been our second option.