San Luis Obispo officials unveiled the city’s new double-decker bus on Tuesday.

The $844,000 bus, paid for mostly through federal grants, begins service today.

City officials said the bus seats 81 people and enabled the city to replace two older buses.

The 14-foot-high vehicle will reduce emissions and serve riders on busy routes, including Cal Poly students, said City Manager Katie Lichtig.

No city general fund money was used to purchase the bus, which also received local funds from the Air Pollution Control District and a state Proposition 1B Bond, said John Webster, the city’s transit manager.