Spatiotemporal structure of traffic flow in a system with an open boundary

The spatiotemporal structure of a traffic flow pattern is investigated under the open boundary condition using the optimal velocity model. The parameter region where the uniform solution is convectively unstable is determined. It is found that a localized perturbation triggers a linearly unstable oscillatory solution out of the linearly unstable uniform state. and it is shown that the oscillatory solution is also convectively stabilized. It is demonstrated that the observed traffic pattern near an on-ramp can be interpreted as the noise sustained structure in the open flow system.