Driving from Zurich to Lucerne and Lucerne to Interlaken

The best route, via the Brunig Pass, between Luzern and Interlaken (although I strongly suggest you go beyond Interlaken into the mountains of the Lauterbrunnen Valley which must be why you are going to Interlaken - Interlaken is NOT in the mountains, it is the gateway but not IN the mountains which are 20 minutes away by train or car - stay in Lauterbrunnen or or one of the car-free villages of Mürren or Wengen, or even one valley over in Grindelwald, depending on what you want to do) is single lane, very hilly as you cross passes, and has several steep hairpin turns as you ascend and descend, and has many tunnels.

The longer in distance route between Luzern and Interlaken is on the flatlands which are more flat, but still not of superhighway size or alignment.

If you want all motorway you would have to go via Zurich and Bern, which is much longer.

It is a very easy ride on the train in all panoramic modern carriages and they are used to luggage. The person who would have driven the car can actually look out the windows of the train as it goes along.

Zurich to Luzern is extremely easy by train, and they are used to luggage, and many of the trains have a family play area complete with slide in the end carriage upstairs.

Zurich to Luzern is easy to drive by car as it is all motorway, but very difficult to park and extremely expensive in both Luzern and Zurich. Zurich has a lot of one way roads and a somewhat complicated traffic pattern. Traffic in both cities can be heavy, especially at peak hours. Expect lots of tunnels.

If you are traveling from one staffed train station to another, SBB has a luggage service:
https://www.sbb.ch/en/station-services/services/luggage-and-flight-luggage.html
We didn't use the luggage service but did see customers retrieving luggage at the station.

Direct trains running from Zurich Airport to Luzern take a little over an hour

Thanks Nigel.This is my second time in Switzerland, I have made Interlaken as the base.The first base is Lucerne.Should I try the Zurich to Lucerne route just then? My last trip I did all train hopping journeys so wish to at least drive 1 route :D Would u suggest how the Zurich to Lucerne route is? If Lucerne to Interlaken is very long route if I happen to drive on flatlands then I would drop that plan.

Thanks Edgar.My only concern is I should not lose any luggage :( I feel it's a risk specially when I m travelling with baby.Do u think their is enough time to board the train if I happen to get inside with 2 check-in bags n 2 cabin bags,the last time I travelled was just 1 cabin bag and 1 check-in bag.So it was a breeze but now I will carry my baby and my better half can carry the luggage but will their be enough time is what i am doubting.

If you don't have enough time between train changes to board your next train onward then just wait for the next one.

The larger train stations (e.g. Zurich Airport and Luzern) have information signs that describe the 1st and 2nd class car sequence and boarding areas (e.g. A, B, C) for those cars. You can pre-position yourselves and baggage on the platform for the appropriate class of travel. The floor of the IR trains between Zurich and Luzern are close to platform level so you do not need to lift bags up steps to get them into the train. However, the IR trains did have lower and upper levels but you can leave the big bags in the bike storage area if you are comfortable not having the bags at your feet. (Being a little paranoid I did keep an eye on the bags at train stops, but Switzerland seems to be pretty safe).

I should add that not all of the Swiss rolling stock is as described above with train floors close to platform level. The narrow gauge regional Rhaetian Railway cars had two stops up from platform level to car level.

Thanks Edgar,if we preposition ourselves at the platform then it would be better.And 5mins obviously the train is going to stop so hoping for the best :) Thanks for the inputs.