The LTA said that when fully deployed, the buses will save close to 8,000 tonnes of carbon dioxide a year. This is equivalent to the amount generated by 1,700 cars.

Besides environmental benefits, passengers can also enjoy commuter-friendly features on these buses, said the LTA. "For example, route information will be displayed digitally on their Passenger Information Display systems. There are no centre poles on these buses, to allow parents with open strollers to board them more easily," it added.

The introduction of the buses is among the LTA's efforts to achieve its goal of having a 100% cleaner energy public bus fleet by 2040, as stated in its Land Transport Master Plan released last year. Public transport operators SMRT, Tower Transit and Go-Ahead Singapore were involved in this launch of electric bus services.

In a Facebook post, Tower Transit said service 66, for which it will deploy electric buses, is the longest service it offers, at five hours for a round trip. Bus Driver Kenny Chow said, "On such a long trip, the quietness and smoothness of the ride can make quite a difference."

There are about 5,800 buses in Singapore. The 60 electric buses - made by Chinese firms Yutong and BYD and local outfit ST Land Systems - were scheduled to arrive progressively from the fourth quarter of last year to the first half of this year. A vehicle powered by an electric motor is far quieter than one powered by a conventional internal combustion engine.

The LTA had said that the ambient noise level of an electric bus is around 75dB, three decibels lower than a typical Euro 6 diesel bus in the current fleet. The electric buses can each carry 80 passengers, split between 28 seated and 52 standing. They take between two and four hours to charge and have a range of between 200km and 300km.