The Riverside Transit Agency (RTA) Roadeo '99 pin is a collectible item that likely commemorates a special event or achievement by the RTA. This pin could feature a design related to buses or taxi cabs, making it a unique and interesting piece for transportation enthusiasts or collectors. Whether the pin was distributed as a token of appreciation or as part of a promotional campaign, it serves as a nostalgic keepsake for those who remember the eventful year of 1999.