Pre-purchased, return train ticket - can you layover?

The regional train tickets you purchased allow 4 hours to complete each trip, Livorno to Lucca and return. Because the standard trip takes only about an hour, you would have time to get off a Pisa S. Rossare, visit the Field of Miracles, walk to Pisa Centrale and catch a later train back to Livorno. That interim stop is permitted, but you must arrive back in Livorno before the 4 hour validity of the ticket expires.

Actually, I read it as once you are on the train in Pisa going back to Livorno, you are OK even if the ticket "expires" while on the train.
Google translate from the Conditions of Carriage.

• Intermediate stops - The traveler can make an unlimited number of stops during the
validity of the ticket.
The traveler who is on the train after the validity of the ticket can continue the journey
already started up to the destination station without intermediate stops except for change
with the first useful train.

By making the intermediate stop, the Conditions of Transport do say that all you have to do is be on the train from Pisa to Livorno when the 4 hour validity expires. That's different from what I was told by the man who sold me a Lucca to Florence via Pisa ticket a few years ago, but now that I think about it the Conditions may have been modified since then. I'll make a point to re-read them.

Great! Thank you very much! I had assumed I'd have to pay for two separate legs, but had read somewhere else that you can layover. That is very nice. Not a huge deal, but it's one less ticket to deal with.

Cheers!
Vivian

The cost for two tickets is usually the same as for a single ticket. The benefit to buying two tickets is you can spend as much time as you wish in the "layover" location. You could buy a return ticket from Lucca to Pisa and then another ticket from Pisa to Livorno. Since there are no discounts for regional tickets you don't need to purchase these in advance and be limited by the 4 hours time limit.

Donna

@Donna, thank you very much for your valued input. Ya, I'm aware of the advantages of buying the tickets there, at the time, but my time will be very tight to make the train I'm hoping for (cruise ship port day), so I want to board as soon as I can in the interest of saving time.

I also happen to have nightmares about buying regional tickets and having to remember to validate them prior to boarding. Stupid, I know, but I had a very disconcerting experience a few years ago which resulted in my being left behind on the platform in Civitavecchia, with all three tickets in hand as I was frantically trying to get them validated, when the train, with my husband and a friend (and my luggage) rolled away toward to Roma Termini. Let's just say it wasn't pretty, and Security swooped down on me. I couldn't speak Italian, nor they, English... before our use of cell phones overseas... I can laugh, now.

Cheers,
Vivian