Citibike has crossed the line, according to angry East Village residents who say a new station was installed last week on the sidewalk of First Avenue, pinching pedestrian space to the size of a pigeon path.

The 51-bike station between 5th and 6th streets should be in the roadway, argued Alice and Arleen Atamanuk, 49-year-old twins who have lived in the same Village View co-op building all their lives.

The now-narrow sidewalk will be troublesome for the many seniors who live there, they said.

“I can see it being annoying,” Arleen said. “It’s taking up more than half the walk area.”

The sisters said the neighborhood has attracted more young people than in the past, including last weekend, when revelers dressed as jolly St. Nick descended on area bars for SantaCon.

“Some people are going to think it’s great,” Alice Atamanuk said of the bikes.

Donald Varley is not one of them.

He was disturbed when his wife noticed the station from their nearby apartment’s window.

Walking his dogs Franklin and Sugar, the 58-year-old was exasperated.

“There’s no room to begin with. It’s ridiculous.”

A Citi Bike spokesperson said the station installed on Dec. 13 is one of many added to sidewalks instead of the street – including one at nearby Tomkins Square Park – but the spokesperson and the Department of Transportation declined to say how many and where they’re located.

The DOT said it looks at travel patterns, utilities, and building and subway entrances when deciding where to place a station.

Joe Cutrufo of Transportation Alternatives, a non-profit that pushes for decreased automobile use, said the bikes are better off in the street, noting about a dozen fit in a single parking spot.

“It’s just a more efficient use of the space.”