I want to go to Pisa from Venice on May 4th. Looking at the Trenitalia train schedules, the following itinerary was proposed: leave the Santa Lucia train station at 8:43 am and arrive in Pisa at 12:59. However there is a connection in Florence. The train from Venice arrives in Florence at 11:23 and then you have to change to a regional train which leaves for Pisa at 11:37. Is 14 minutes enough time to change trains? I am concerned because I am not familiar with the train station in Florence.
Certainly, that is enough time to switch trains. Just make sure you look at the departures board to see which platform you will be departing from and head over there.
The only concern is that Italian trains are not always perfectly accurate, but the first route that you will be taking from Venice to Florence is probably on an ES (Eurostar Italia), which has a better on-time record.
Just remember that the ES trains require mandatory reservations, so if you are travelling with a pass instead of point-to-point tickets, you will need to purchase an additional reservation before you board the train.
Not to worry. When you get your tickets, you will receive a separate ticket for each train you will be on. Thus, for Venice to Pisa, you will have two tickets. The first one will most likely be on a Eurostar-class train. This ticket will have a date, train number and seat assignment on it.
The reason for mentioning all that is that your second ticket most likely wont' have all of this info. Most trains from Florence to Pisa are Regionale (R) trains. These are the locals. Your ticket will show a 60-day period beginning from when you purchased it. That's it. No train number, date or seat assignment. It's called an open ticket. You can take any R train making that same run within 60 days.
Now my point. You do have time to make the train change. As I recall, there are 15 tracks at the Florence train station. Once you get off your Eurostar, look to the front of the station and look at the large electronic sign board to see which trains are leaving on which track. BIG HINT: your train to Pisa may not say Pisa on the large board. The train, as well as the sign board, shows the final destination of the train and not the cities where it stops. Pisa is a major stop but not a major train destination. The sign board will show the departure time. Yours to Pisa is 11:37 and that should get you close.
Now the much better news. There are numerous trains a day departing Florence for Pisa. You should be able to make the 11:37. However, if you don't, the next train to Pisa departs 20 minutes later at 11:57. Your open ticket is good on either train. Be sure to validate the ticket at one of the several lemon-yellow boxes in the station. Once validated, your 60-day ticket is now only good for 6 hours. Hope this helps.