Urban Air Mobility (UAM) relies on vertical take-off and landing (VTOL) aircraft operating in metropolitan areas. Early operations are likely be conducted under Visual Flight Rules (VFR). Future high-density operations may incorporate a wide-range of VTOL aircraft, including remotely piloted and autonomous. Urban vertiports are potential chokepoints for UAM operations and will need some form of traffic management to maintain safe and efficient operations. Providing traditional air traffic control (ATC) services at each vertiport would be costly. Vertiport automation is needed to provide real-time air traffic and information services. The proposed Vertiport Traffic Automation System (VTAS) accommodates low-density VFR operations in the near-term and can evolve to handle future high-density, autonomous operations at close-proximity vertiports. A flexible service-based architecture adapts to vertiports with different configurations and traffic patterns; integrates with other UAM Service Suppliers; and provides an open platform for the automation to evolve as UAM operations increase. Potential NASA Applications (Limit 1500 characters, approximately 150 words) VTAS can support NASAs ATM eXploration (ATM-X) Projects UAM Subproject, including demonstrations by NASA and industry partners, such as those planned under the UAM Grand Challenge. VTAS can be integrated with the UAM Airspace Management System NASA is developing and provide a platform for hosting experimental vertiport services and capabilities. VTAS can provide a platform for researching and testing In-time System-wide Safety Assurance (ISSA) monitor, assess, and mitigate functions for NASA System-Wide Safety (SWS) Project. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words) In the long-term VTAS can support commercial operators developing and planning UAM air taxi services, such as Uber Elevate, Joby Aviation, Kitty Hawk, Airbus, and Volocopter. In the near-term VTAS can improve services at privately operated vertiports and heliports.