If not restricted by tolls, private decisions to drive on a highway result in inefficiently high usage which leads to traffic jams. When traffic demand is high, traffic jams can occur simply because of the interaction of vehicle drivers on the road, a phenomenon called phantom jam. The probability of phantom jams occurring increases with traffic flow. Unpriced externalities lead to inefficiently high road usage. We offer a method for quantifying traffic jam externalities and identifying and isolating the phantom jam externality. We examine the method by applying it to a specific highway section in Germany. The maximal congestion externality for the analyzed highway section is about 38 cents per vehicle and kilometer. Congestion charges that are calculated ignoring phantom jam externalities, can only internalize two-thirds of the true externality.

中文翻译：

---

量化幻像卡纸的外部性：德国高速公路部分的案例

如果不受通行费的限制，私人决定在高速公路上行驶会导致效率低下的高使用率，从而导致交通拥堵。当交通需求高时，仅由于道路上车辆驾驶员的相互作用而可能发生交通堵塞，这种现象称为幻影堵塞。幻影卡塞发生的可能性随着交通流量的增加而增加。无法估量的外部性导致低效率的道路使用。我们提供一种量化交通拥堵外部性并识别和隔离幻像拥堵外部性的方法。我们通过将其应用于德国特定的高速公路路段来研究该方法。经分析的高速公路路段的最大拥堵外部性为每辆汽车每公里38美分。忽略幻象果酱外部性而计算出的拥堵费只能内部化真正外部性的三分之二。