The eco-friendly initiative, called Ricicli+Viaggi (Recycle + Travel) was launched this week and will run for 12-months as a trial, at three metro stations in the city; Cipro station Line A, Piramide Line B and San Giovanni Line C.
Each bottle recycled from 0.25cl to 2 litres is worth the equivalent of five euro cents in points, meaning commuters need to recycle 30 bottles to accumulate enough points for a €1.50 ticket.
The points are then transferred onto a My Cicero or TabNet apps, operated by public transport authority ATAC.
Virginia Raggi, mayor, Rome, said in March she wants to introduce a ban on single use plastic as the council continues to struggle with the city's rubbish problem.
Italy is the fourth most-wasteful country in Europe, producing enough rubbish to fill the Colosseum over 12 times, according to a 2017 report by the consultancy group Expert Market.
Things worsened further in 2013, when the city's sprawling Malagrotta tip was found to fall short of European standards and ordered to close.
The council has struggled ever since to find an alternative, and the city's refuse system regularly reaches crisis point in busy periods.
According to Raggi the rubbish problem is created by organised crime gangs dealing in waste, known as "ecomafia".
This isn’t the first time a campaign of this kind has been introduced; last year a subway station in Istanbul, Turkey installed vending machines that recycle used aluminium cans and plastic bottles in exchange for train fares.
İTÜ-Ayazağa metro station in Maslak, Turkey’s second-largest financial district, now accepts recyclable cans and bottles as train fare.
Customers can top up their city transportation pass (Istanbul Card) by feeding the reverse vending machines with recyclable plastic bottles and aluminium cans.
The machines will crush, shred and sort out the recyclable waste. According to the New York Times, the city wants to introduce 100 more at 25 locations, including schools and universities before the year is out.
A 0.33-litre plastic bottle will get two kurus credit (kurus is the Turkish equivalent of cents, 100 kurus make up one lira), while a 0.5-litre bottle would add about three kurus in credit; a one-litre bottle will get you six kurus ($1.1 cents) and a 1.5-litre bottle will add nine kurus ($1.6 cents) to your card.
With the average subway journey costing approximately 2.60 Turkish lira ($40 cents), a commuter would need to crush at least 28 1.5-litre bottles to have enough credit for a free ride.
With aluminium cans an average 0.5-litre can top up your card with nine kurus credit.
Speaking about the initiative in Italy, Paolo Simoni, president, Atac, said: “In a period in which crypto-currency is talked about, we have plastic currency. Substantially, it’s a system in which one recycles, we build customer loyalty and citizens’ virtuous behaviour is rewarded.”
The campaign has attracted the attention of policy makers in other Italian cities, which have expressed their interest in testing similar schemes. The reaction from the public has also been very positive, with 11,000 plastic bottles being collected in less than one week from the launch of the trial.