Our bright blue Citibike, number 0919, starts its day early at the busiest Citibike station, on 42nd Street, outside Grand Central station. Last month, nearly 500 trips started or ended here every day.7.50am Yuri K, 39, rushes towards Citibike 0919. He just got off the train from Westchester, Connecticut, and is on his way to his office in Tribeca in downtown Manhattan. "Yes, you can follow me," he says as he puts on his blue helmet. "I hope you don't mind going in the wrong direction on some streets."