Abstract Based on a study of probe vehicle data measured on different highways during different days we have revealed some common empirical microscopic characteristic features of sequences of phase transitions from free flow to synchronized flow and back from synchronized flow to free flow occurring before traffic breakdown at a highway bottleneck predicted theoretically by Kerner. Following common empirical features of sequences of these phase transitions have been found: (i) Sequences of empirical phase transitions from free flow to synchronized flow and back from synchronized flow to free flow are observed on different highways at different bottlenecks. (ii) Empirical sequences of the phase transitions exhibit a random character, in particular, at different days very different sequences of phase transitions from free flow to synchronized flow and back from synchronized flow to free flow have been observed at the same bottleneck. (iii) Time durations between the transition from free flow to synchronized flow and the subsequent transition from synchronized flow to free flow within a sequence of the phase transitions are random values. Time intervals between subsequent sequences of the phase transitions are also random values. (iv) Regions of dissolving synchronized flow that result from sequences of phase transitions from free flow to synchronized flow and back from synchronized flow to free flow exhibit random characteristics. (v) Several following each other sequences of phase transitions from free flow to synchronized flow and back from synchronized flow to free flow can lead to waves of synchronized flow between free flow.

中文翻译：

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高速公路瓶颈处自由流动和同步流动之间的经验随机相变

摘要 基于对不同天数在不同高速公路上测量的探测车辆数据的研究，我们揭示了一些共同的经验微观特征，即在交通中断之前发生的从自由流到同步流和从同步流返回到自由流的相变序列的一些共同经验微观特征。克纳理论预测的高速公路瓶颈。已发现以下这些相变序列的共同经验特征： (i) 在不同瓶颈的不同高速公路上观察到从自由流到同步流和从同步流返回到自由流的经验相变序列。(ii) 相变的经验序列表现出随机性，特别是，在不同的日子里，在同一瓶颈处观察到了从自由流动到同步流动和从同步流动回到自由流动的非常不同的相变序列。(iii) 相变序列内从自由流动到同步流动的过渡和随后从同步流动到自由流动的过渡之间的持续时间是随机值。相变的后续序列之间的时间间隔也是随机值。(iv) 由从自由流到同步流和从同步流返回到自由流的相变序列产生的溶解同步流区域表现出随机特性。