Driving from Spain (thru France) to Italy, Switzerland, and then Paris

You can get suggested routes and driving time estimates at www.viamichelin.com. You can drive most of the way on motorways (freeways), but you'll have to pay tolls to do so. Secondary routes (no tolls) will be much slower.

Have you checked with a consolidator like www.autoeurope.com for rental costs? Are you aware that there will be a sizeable fee for picking up a car in one country and dropping it off in another? Have you thought about what a hindrance a car will be in each city you visit?

Consider flying on a budget airline from Barcelona to Venice. According to www.whichbudget.com, your choices are MyAir, clickair, Vueling, and alpieagles. Then take the train for your other routes and use public transportation in each city.

Tim,

Thank you for your response.

How much are the tolls? Are they like the $5 tolls we get on bridges here? Or are they really expensive?

We've already looked at car rental prices are they are not too much, considering. We know we'll be happier in a car. Plus the freedom it offers, to stay, stop, and leave when we want to, rather than have to schedule around train or plane schedules. And in a car we can stop to check out the sights everywhere we pass through.

And other than Paris, where we'll be staying for longer, and dropping off the car as soon as we get there, we'll only be spending a night or two in each city.

The Michelin site also gives estimates for gas and tolls. Example: for Barcelona-Venice the estimate is 117 EUR for gas and 87 EUR for tolls.