There are basically three categories of direct trains between Milan and Venice: the most frequent (nearly hourly) are the Eurostar-City (ES-City), the fastest (by 15 minutes) are the regular Eurostars (ES), and the cheapest by half are the regionale (R) trains.
The overwhelming odds are that you will travel on one of the hourly ES-City trains, where a second class ticket costs 27.60 Euros. You may be able to save 20% by booking the "AMICA" fare no later than midnight of the day before travel. The ES-City makes six stops en-route.
The couple of regular ES trains cost almost 5 Euros more, but save only 15 minutes of travel time, and they stop only in Padova and Mestre!!! The "AMICA' fare is NOT available on the regular ES train. There is a 15% discount fare, which requires a minimum 7-day advance purchase.
The ES-City is a "cross" between the ES and the IC train. Railcars are the same as those on the IC train, but there is more "open railcar" seating as on ES trains, rather than the separate enclosed seating compartments of the traditional IC trains. The exterior of the ES-City has a different color scheme to distinguish it from the IC trains.
Travellers on a budget will be happy to know that there remain several direct R trains between Milan and Venice. Travel time is 60 minutes more than the ES-City, but the fare in second class is nearly one-half: a cheap 14.50 Euros. This fare is non-discountable. The R train makes 15 stops en-route.
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