Treiber M, Hennecke A, Helbing D
II. Institute of Theoretical Physics, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Aug;62(2 Pt A):1805-24. doi: 10.1103/physreve.62.1805.
We present data from several German freeways showing different kinds of congested traffic forming near road inhomogeneities, specifically lane closings, intersections, or uphill gradients. The states are localized or extended, homogeneous or oscillating. Combined states are observed as well, like the coexistence of moving localized clusters and clusters pinned at road inhomogeneities, or regions of oscillating congested traffic upstream of nearly homogeneous congested traffic. The experimental findings are consistent with a recently proposed theoretical phase diagram for traffic near on-ramps [D. Helbing, A. Hennecke, and M. Treiber, Phys. Rev. Lett. 82, 4360 (1999)]. We simulate these situations with a continuous microscopic single-lane model, the "intelligent driver model," using empirical boundary conditions. All observations, including the coexistence of states, are qualitatively reproduced by describing inhomogeneities with local variations of one model parameter. We show that the results of the microscopic model can be understood by formulating the theoretical phase diagram for bottlenecks in a more general way. In particular, a local drop of the road capacity induced by parameter variations has essentially the same effect as an on-ramp.
我们展示了来自德国几条高速公路的数据，这些数据显示在道路不均匀处（特别是车道封闭处、十字路口或上坡路段）附近会形成不同类型的拥堵交通。这些状态可以是局部的或扩展的、均匀的或振荡的。也观察到了组合状态，例如移动的局部拥堵集群与固定在道路不均匀处的集群共存，或者在几乎均匀的拥堵交通上游出现振荡拥堵交通区域。实验结果与最近提出的关于匝道附近交通的理论相图一致[D. 赫尔宾、A. 亨内克和 M. 特里伯，《物理评论快报》82, 4360 (1999)]。我们使用经验边界条件，通过连续微观单车道模型“智能驾驶员模型”对这些情况进行模拟。通过用一个模型参数的局部变化来描述不均匀性，所有观测结果，包括状态的共存，都能得到定性再现。我们表明，通过以更一般的方式构建瓶颈的理论相图，可以理解微观模型的结果。特别是，由参数变化引起的道路容量局部下降与匝道具有基本相同的效果。
