Predominantly a boat city, where most of the residents commute by walking, in Venice there are no cars, motorcycles or buses running here beyond Piazzale Roma.  Tronchetto is a man-made island which has a large parking garage where visitors from the mainland park their cars, or in the smaller car parks around Piazzale Roma. After that one does not need a car during the whole stay. There are several water buses standing along Piazzale Roma and generally all over Venice. In Lido, however car, buses etc can be seen on the streets.
The water taxi is the fastest but also the most expensive way to move around in Venice. These water taxis have a closed cabin and are very comfortable to travel in regardless of the weather conditions. Taxis are available at the several water taxi ranks or the hotel you are staying at could call one for you. Taxi fare can be paid at the hotel. An extra amount is charged for night service, waiting time and luggage.
Only travel in a legitimate water taxi that has serial number in black on yellow background and be sure to ask the driver to turn on the meter. To view official water taxi fares visit the Venice City Hall website