Berner Oberland by car: A8 Motorway stops between Lucerne and Lauterbrunnen?

The motorway between Luzern (local spelling, you won't find Lucerne on any road signs) is a motorway in name but is mostly a two lane road with a solid line down the middle - very few opportunities to pass. I was stuck behind a tour bus all the way from Brienz to just before Luzern one year.

I will say that I have never done that road at this time of year, and you will likely run into standing snow at the higher altitudes of the pass but probably not on the road itself. The road can be quite steep - it runs next to the train (which I prefer on that route) which is a cog railway for much of the route.

There are lots of tunnels along the route which speeds up the transit time but removes the views. Near the entrance to most tunnels there is the option to go onto local roads and return to the lake side or rural areas. There are plenty of turn outs and parking areas and view points, especially at and near the Brunig Pass. I don't know what snow there might be piled up in the view points.

Meiringen is on the route, at the bottom of all the switchbacks coming down steeply to Brienz lake level, and is where Sherlock Holmes had such a run in with death at the hands of Moriarty. The falls is there - Reichenbach Falls - and has an ancient funicular much of the way up, but I don't know what would be open in March.

March, especially the end of March, is really too late for skiing as the thaw begins, and too early for hiking unless you want slushy muddy boots, but it could do anything with little notice.

Have a look at the trails at https://www.jungfrau.ch/en-gb/winter-hiking/

As Nigel says, there are a bunch of tunnels around the towns that were built a few years back but they're easy to bypass. Turnoffs will generally be on the right and will list the town name - use them for the views. You'll pass a bunch of lakes and scenic towns along the way between Luzern and the Brunig. If you're into antiques, there's a nice antique shop across the street from the Brunig station. If you want a great souvenir, they sell real cowbells from some of the farms that have shut down in the area. Its super sad, but an unfortunate fact of life in Switzerland. Meiringen is a decent place with some sights, as noted above. Brienz is a nice woodcarver's town with some nice shops, but do venture up through the town moving westwards from where the station is (the cute architecture is often on the little small lanes). Its gotten more touristy of late but its still nice. A nice little trip from Brienz is taking a boat ride on lake Brienz. Personally I'd take one that leaves Brienz and heads westward, docking in one of the small towns on the north shore. Then take the train back to Brienz (the station is generally across the street or slightly uphill from the dock). Minimally you'll have one train per hour. There's also a nice open air museum (the Ballenberg) between Meiringen and Brienz; I've never been there but I hear its wonderful. Another nice detour is from Giswil up towards Sorenberg (just go to the top of the pass, not into Sorenberg). The views of the lakes and alps from up there is outstanding; you'll also pass many small traditional farms along the way. Odds are the cows wont be out yet, but they might - you never know.

Thanks so much! I will take all this advise into account while planning the trip.