Traffic signal control at intersections, especially in arterial networks, is a key lever for mitigating the growing issue of traffic congestion in cities. Despite the widespread deployment of SCOOTS and SCATS, which prioritize efficiency, fairness has remained largely absent from their design logic, often resulting in unfair outcomes for certain road users, such as excessive waiting times. Fairness however, is a major driver of public acceptance for implementation of new controll systems. Therefore, this work proposes FairSCOSCA, a fairness-enhancing extension to these systems, featuring two novel yet practical design adaptations grounded in multiple normative fairness definitions: (1) green phase optimization incorporating cumulative waiting times, and (2) early termination of underutilized green phases. Those extensions ensure fairer distributions of green times. Evaluated in a calibrated microsimulation case study of the arterial network in Esslingen am Neckar (Germany), FairSCOSCA demonstrates substantial improvements across multiple fairness dimensions (Egalitarian, Rawlsian, Utilitarian, and Harsanyian) without sacrificing traffic efficiency. Compared against Fixed-Cycle, Max-Pressure, and standard SCOOTS/SCATS controllers, FairSCOSCA significantly reduces excessive waiting times, delay inequality and horizontal discrimination between arterial and feeder roads. This work contributes to the growing literature on equitable traffic control by bridging the gap between fairness theory and the practical enhancement of globally deployed signal systems. Open source implementation available on GitHub.

翻译：交叉口信号控制，特别是在主干道路网中，是缓解城市日益严重的交通拥堵问题的关键手段。尽管SCOOTS和SCATS系统已广泛部署并优先考虑效率，但其设计逻辑中基本未纳入公平性考量，常导致某些道路使用者（如承受过长等待时间）遭遇不公结果。然而，公平性是公众接受新控制系统实施的主要驱动力。为此，本研究提出FairSCOSCA——一种面向上述系统的公平性增强扩展方案，其包含两项基于多种规范性公平定义的新颖且实用的设计改进：（1）纳入累积等待时间的绿灯相位优化，以及（2）对低利用率绿灯相位的提前终止。这些扩展确保了绿灯时间更公平的分配。通过在德国埃斯林根内卡河主干道路网校准微观仿真案例中的评估，FairSCOSCA在多个公平维度（平等主义、罗尔斯主义、功利主义及哈桑尼主义）上均展现出显著改善，且未牺牲交通效率。与固定周期、最大压力及标准SCOOTS/SCATS控制器相比，FairSCOSCA显著减少了过长等待时间、延误不平等性以及主干道与支路间的横向歧视。本研究通过弥合公平性理论与全球部署信号系统实际增强之间的鸿沟，为日益增长的公平交通控制文献作出了贡献。开源实现已发布于GitHub。