Hi pete;
Just to say that we had a very successful trip to Venice last year, towing a large twin axle van. No problems at all. We went via France and Switzerland - the french tolls are not too onerous, and I prefer driving in France to Germany, as the traffic is generally lighter, the roads are better maintained and the journey a little more relaxed. We do normally enter Switzerland via the short stretch of German motorway to transit Basel (easy route), we then stopped on this trip for a couple of nights at Lucerne, beautiful city (great site near the transport museum); we then moved south via the St Gotthard route (motorway/ tunnel - no problems for the van) and stopped for a few days on the shore of Lake Lugano in southern Switzerland, and enjoyed the area there (Lugano worth a visit). From there we drove into Italy and on to Venice - easy day on the motorway (heavy traffic near Milan though!). For a stay at Venice I highly recommend Camping Fusina (they have a website), which is on the shore of the lagoon south of the city - you can get a waterside pitch and look straight across at St Marks etc, and best of all the vaporetto (water bus) service calls at a stop just outside the site gate and takes you direct to the city centre. You won't need to move your car and you can get a travelcard type ticket to hop to and fro and really enjoy the place. Venice is as beautiful as you would ever hope - and I think the way to arrive is via boat into the true heart of the old city. Be aware that from some sites to the north of Venice you will actually need to get a bus or a train to the 'inland' side of the city (Piazza Roma or St Lucia stn), which is not the best part, and is a long walk to St Marks/Rialto areas. We have also towed into Italy via Geneva and Chamonix valley and then using the Mont Blanc Tunnel, this is also an excellent route, all motorways, and very suitable for a large 'van. The Swiss vignettes aren't cheap, but if you consider the journey as part of the holiday then Switzerland is a good option and the roads are excellent. At the end of the day it's all down to personal choice - Enjoy your travels!
Richard