The change, which seeks to afford commuters more time to adjust and explore new travel routes, will take effect from 17 December.
Effective from 10 December 2023, adjustments to bus services and routes are aimed at improving connectivity and complementing rail services.
According to a statement by the Land Transport Authority on Monday, bus services are now more reliable and less crowded, thanks to a new bus contracting model.
SMRT said that it had trained five bus captains to familiarise them with the operations of the new three-door bus, and will train more in the future.
The three-door double-decker is 0.8m longer than the usual 12m, and the Land Transport Authority will evaluate if it is suitable for the current infrastructure.
Besides having three doors, the buses will feature other friendly features such as a passenger information display system, USB ports and wheelchair space.
Singapore's newest bus operator - U.K.-based company Go-Ahead - has launched 13 bus services in Punggol, with 11 more to be launched in two weeks' time.
The first weekday of operations for new bus operator Tower Transit went smoothly, with few commuters noticing the difference after the switch.