  As a healthy and green transportation mode, cycling has been advocated by
many governments. However, compared with vast amounts of works on vehicle flow
and pedestrian flow, the bicycle flow study currently lags far behind. We have
carried out experimental studies on bicycle flow on a 146-m long circular road.
We present the fundamental diagram of bicycle flow and the trajectories of each
bicycle. We have analyzed the spatiotemporal evolution of bicycle flow as well
as its stability and phase transition behavior. The similarity between bicycle
flow and vehicle flow has been discussed. We have proposed a cellular automaton
model of bicycle flow, and the simulation results are in good agreement with
the experiments.
