The MTA's new double-decker bus service offers riders something new: Unobstructed views of the city.

"The view is amazing," commuter Antwon Hechmi said on the upper level of a bus. "It's a birds-eye view, you can see everything from here."

The double-decker is being tested on one route, the X17J, express service between Eltingville on Staten Island and Midtown.

The MTA is intrigued because it seats 81 people, compared to 57 passengers on standard buses. The extra capacity accommodates more commuters without adding traffic to the city's congested streets.

"It's pretty cool to have double-decker buses on the MTA," Michael Peleshenko of Eltingville said. "More seats is always welcome, and it's a nice shiny new look for the MTA."

The double-decker takes up less road space than the MTA's articulated buses, those extra-long buses that are essentially two vehicles operating as one.

"It's about time, you would think," Dyker Heights resident George Velez said. "Those long buses in Manhattan, it's crazy with traffic."

The bus is 12 feet, 10 inches tall, just short enough to fit through the 13-foot Lincoln Tunnel.

But while the extra height can accommodate more passengers, the double-decker requires some ducking.

"I banged my head on the top of the ceiling when I first got up here, so they could have done a little better with the head room," Hechmi said.

Bus driver Stacey Fiora on Tuesday was acting as a type of good will ambassador for the two-tiered bus, passing out brochures and informing riders what was going on.

"I also tell people watch their heads because the ceilings are a little low, use the handrails going up the stairs because they're not used to the stairs, it's new for New York," Fiora said. "They're a little bit in shock when they see the bus coming, but I'm just like, 'Come on, it's just a regular bus, get on, it's ok.'"

MTA officials said the buses, which do take riders some time to get on and off, are a better fit for longer routes that make fewer stops.

If the pilot program is successful, the agency plans to roll out more double-deckers.