Congestion pricing has long been hailed as a means to mitigate traffic congestion; however, its practical adoption has been limited due to the resulting social inequity issue, e.g., low-income users are priced out off certain roads. This issue has spurred interest in the design of equitable mechanisms that aim to refund the collected toll revenues as lump-sum transfers to users. Although revenue refunding has been extensively studied for over three decades, there has been no thorough characterization of how such schemes can be designed to simultaneously achieve system efficiency and equity objectives. In this work, we bridge this gap through the study of \emph{congestion pricing and revenue refunding} (CPRR) schemes in non-atomic congestion games. We first develop CPRR schemes, which in comparison to the untolled case, simultaneously increase system efficiency without worsening wealth inequality, while being \emph{user-favorable}: irrespective of their initial wealth or values-of-time (which may differ across users), users would experience a lower travel cost after the implementation of the proposed scheme. We then characterize the set of optimal user-favorable CPRR schemes that simultaneously maximize system efficiency and minimize wealth inequality. Finally, we provide a concrete methodology for computing optimal CPRR schemes and also highlight additional equilibrium properties of these schemes under different models of user behavior. Overall, our work demonstrates that through appropriate refunding policies we can design user-favorable CPRR schemes that maximize system efficiency while reducing wealth inequality.

翻译：拥堵收费长期以来被视为缓解交通拥堵的一种手段，然而，其实际应用因导致的社会公平问题而受到限制，例如低收入用户被某些道路的高收费排斥在外。这一问题激发了人们对设计公平机制的兴趣，这些机制旨在将收取的通行费收入以一次性转移的方式返还给用户。尽管收入返还已被广泛研究了三十多年，但关于如何设计此类方案以同时实现系统效率和公平目标，一直缺乏深入的特征分析。在本研究中，我们通过研究非原子拥堵博弈中的拥堵收费与收入返还方案，填补了这一空白。我们首先开发了拥堵收费与收入返还方案，与未收费情况相比，该方案能在不加剧财富不平等的同时提高系统效率，并且是用户友好的：无论用户的初始财富或时间价值（可能因用户而异）如何，实施提议方案后，他们的出行成本都会降低。接着，我们刻画了同时最大化系统效率和最小化财富不平等的最优用户友好型拥堵收费与收入返还方案的集合。最后，我们提供了计算最优拥堵收费与收入返还方案的具体方法，并强调了在不同用户行为模型下这些方案的额外均衡性质。总体而言，我们的工作表明，通过适当的返还政策，我们可以设计出既能最大化系统效率又能减少财富不平等的用户友好型拥堵收费与收入返还方案。