Ljubljana to Split

Do you have enough time to make a stopover? Zagreb would be the obvious choice--you can continue in from there with a car or use the bus.

We are going the opposite direction. Driving from Split to Zagreb; dropping off the car. We will either take the train to Llublijana, or use a shuttle service such as Mydaytrip.com

A tricky connection, as you have found.

No direct (nonstop) flights. Flights tend to be multistop, expensive, have horrible layovers, or some combination of those.

Trains will require a stop in Zagreb and will take a long time (10 hours or more). Bus is about as long.

Driving takes about 5 hours, but you'll get a nasty drop-off fee.

You could rent two cars, one from Ljubljana to a Slovenian bordertown, drop that car there; taxi or bus across to the next Croatian bordertown, pick up your Croatia car there. A bit of a schlepp but that's what I did once. It's hard to find towns right on both sides of the border with car rental agencies, but worth checking if you are up a minor adventure. I was able to make it work dropping our Slovenia car in Portoroz, took a bus to Rovinj in Croatia, picked up another car there. It was a bit crazy but the dropoff fee would have been crushing.

No great options. Choose the least-bad option and make your peace with it (or take a fresh look at your overall plan and see if there's a better/different way you might go).

I did this connection the opposite way in October. I took the train to Zagreb, spent the night there, and took another train the next day to Ljubljana. If there had been a direct flight, I might have taken it. But I hadn't been to Zagreb in a long time so I decided to spend a night there and enjoy an evening/morning there. And I love trains. I was looking forward to the train rides.

But the train from Split to Zagreb was awful - a short train with only two cars, and the seats were very cramped even the tiny first class section (could not see what different there was between first and second class on this train). I got stuck next to a large person so spent half of the ride standing between cars. The train was pretty full. I hate buses usually, but in retrospect I probably should have taken the bus to Zagreb. It's quicker than the train, though I wouldn't have been able to stand on the bus. (The train from Zagreb to Ljubljana was much nicer. Not crowded, no reservations, so I could get up and move if need be to another seat.)

Taking the train from Ljubljana to Rjeka or to Zagreb and then renting a car one way (drop fee probably but at least smaller, dropping in same country) might make more sense. The drive from Zagreb or Rjeka to Split is about the same driving distance I think. (I've driven it both ways.) Although you'd think driving closer to the coast from Rjeka to Split would be more scenic, the fast highway is mostly inland. There's a slower coastal road (I did not take) which would probably be more scenic but a lot slower.

If you can break up your journey with an overnight stay, you could of course stop in Zagreb which would make some sense, then take the direct bus the next day to Split (how I would do it now not the train of course). Since the bus ride from Zagreb to Split probably won't have many stops and it's mostly modern highway, it might not be bad.

Renting a car in Zagreb also means you could stop for a night at Plitvice Lakes National Park, if you have time - highly recommended.

If you really don't have time to stop and want to get there ASAP, flying might be easiest, even if you have to make a connection somewhere. Just remember to add an extra hour or so to get from Split airport into town.

We took the bus to Zagreb from Ljubljana and then the next day we took another bus to Split. I believe there is also a train connection from Zagreb to Split, but we had great experiences using FlixBus.