Abstract: Vehicles in transit within a location may transmit and/or receive information about transit events arising within the location, such as accidents, developing weather, and road obstructions. Because localized exchange channels, such as a radiofrequency broadcast, may be range-limited and/or unreliable, a centralized service may be provided to facilitate the exchange of notifications about transit events, but it may be difficult to provide a centralized service that is both scalable to millions of vehicles and capable of low-latency exchange of time-sensitive notifications for transit events. The techniques presented herein provide an architecture for broadcasting transit events through a transit service that maintains vehicle area groups, respectively identifying the vehicles that are associated with each location.