In upcoming years, the introduction of autonomous vehicles (AVs) will reshape the transport system. The transition from a regular to an autonomous transport system, however, will take place over many years and lead to a long period with a mixed driving environment where AVs and regular vehicles (RVs) operate side by side. The purpose of this study is to investigate how the utilisation of the road capacity degrades as a function of heterogeneity in congested motorways. The analysis is based on a dedicated traffic simulator, which enables the investigation of complex dynamic spillback from congestion while allowing for different degrees of heterogeneity. The representation of autonomous vehicles is based on a modified intelligent driver model (IIDM) presented by Treiber et al. (Phys Rev E 62(2):1805–1824, 2000) and Treiber and Kesting (Traffic flow dynamics, Springer, Heidelberg, 2013), while the behaviour of drivers of RVs relies on a stochastic version of the IIDM. Three main conclusions stand out. Firstly, it is shown that in an idealised environment in which AVs operate alone, a substantially improved capacity utilisation can be attained. Secondly, when drivers of RVs are mixed with AVs, capacity utilisation degrades very fast as a function of the share of RVs. Thirdly, it is shown that the improved capacity utilisation of AVs comes in the form of reduced travel time and increased throughput, with indications that travel time reductions are the most important. From a strategical planning perspective, the results underline that dedicated lanes are preferable to attain the positive effects of AVs. Specifically, we compare a stylised situation with three lanes with a share of 33% AVs to a situation with two regular lanes and a single dedicated AV lane. The latter represents a tripling in consumer surplus all other things being equal.

中文翻译：

---

混合高速公路交通中的自动驾驶汽车：容量利用、影响和政策含义

在未来几年，自动驾驶汽车 (AV) 的引入将重塑交通系统。然而，从常规交通系统到自主交通系统的过渡将持续多年，并导致长期混合驾驶环境，其中 AV 和常规车辆 (RV) 并排运行。本研究的目的是调查道路通行能力的利用如何作为拥挤高速公路的异质性的函数而下降。该分析基于专用的交通模拟器，该模拟器能够在允许不同程度的异质性的同时调查来自拥堵的复杂动态回溢。自动驾驶汽车的表示基于 Treiber 等人提出的修改后的智能驾驶员模型 (IIDM)。(Phys Rev E 62(2):1805–1824, 2000）以及 Treiber 和 Kesting（交通流动力学，Springer，海德堡，2013），而 RV 驾驶员的行为依赖于随机版本的 IIDM。三个主要结论脱颖而出。首先，它表明在理想化的环境中，自动驾驶汽车单独运行，可以显着提高容量利用率。其次，当 RV 的驱动程序与 AV 混合时，作为 RV 份额的函数，容量利用率下降得非常快。第三，显示 AV 容量利用率的提高以减少旅行时间和增加吞吐量的形式出现，有迹象表明减少旅行时间是最重要的。从战略规划的角度来看，结果强调专用车道更可取地获得自动驾驶汽车的积极影响。具体来说，我们将具有 33% AV 份额的三个车道的程式化情况与具有两个常规车道和单个专用 AV 车道的情况进行比较。在其他条件相同的情况下，后者代表了消费者剩余的三倍。