The increasing wireless communication capabilities of vehicles creates opportunities for more efficient intersection management strategies. One promising approach is the replacement of traffic lights with a system wherein vehicles run protocols among themselves to determine right of way. In this paper, we define the intersection problem to model this scenario abstractly, without any assumptions on the specific structure of the intersection or a bound on the number of vehicles. Protocols solving the intersection problem must guarantee safety (no collisions) and liveness (every vehicle eventually goes through). In addition, we would like these protocols to satisfy various optimality criteria, some of which turn out to be achievable only in a subset of the contexts. In particular, we show a partial equivalence between eliminating unnecessary waiting, a criterion of interest in the distributed mutual-exclusion literature, and a notion of optimality that we define called lexicographical optimality. We then introduce a framework to design protocols for the intersection problem by converting an intersection policy, which is based on a global view of the intersection, to a protocol that can be run by the vehicles through the use of knowledge-based programs. Our protocols are shown to guarantee safety and liveness while also being optimal under sufficient conditions on the context. Finally, we investigate protocols in the presence of faulty vehicles that experience communication failures and older vehicles with limited communication capabilities. We show that intersection protocols can be made safe, live and optimal even in the presence of faulty behavior.

翻译：车辆无线通信能力的日益增强为更高效的交叉口管理策略创造了机遇。一种前景广阔的方法是用车辆间运行协议以确定通行权的系统取代交通信号灯。本文中，我们定义了交叉口问题以抽象地建模该场景，不对交叉口的具体结构或车辆数量设置任何限制。解决交叉口问题的协议必须保证安全性（无碰撞）和活性（所有车辆最终都能通过）。此外，我们希望这些协议满足各种最优性标准，其中某些标准仅在特定情境下可实现。特别地，我们证明了消除不必要等待（分布式互斥文献中的关注标准）与我们定义的词典最优性概念之间的部分等价关系。随后，我们引入一个框架，通过将基于交叉口全局视角的交叉口策略转换为车辆可运行的知识型程序协议，来设计交叉口问题的协议。我们的协议被证明在保证安全性和活性的同时，还能在满足情境充分条件时达到最优。最后，我们研究了存在通信故障的故障车辆和通信能力有限的老旧车辆时的协议。研究表明，即使在存在故障行为的情况下，交叉口协议仍可实现安全、活性和最优性。