RA: Registration Authority
RAC: Royal Automobile Club
RAD-IT: Regional Architecture Development for Intelligent Transportation
RASDS: Reference Architecture for Space Data Systems
RCVW: Railroad Crossing Violation Warning
RESCUME: Response, Emergency, Staging, and Communications, Uniform Management, and Evacuation
RESP-STG: Incident Scene Pre-Arrival Staging Guidance for Emergency Responders
RF: Radio Frequency
RFI: Request For Information
RFID: Radio Frequency Identification
RFP: Request For Proposal
RFQ: Request for Quotation
RFQ: Request For Qualifications
RITA: Research and Innovative Technology Administration
RLVW: Red Light Violation Warning
RLW: Restricted Lane Warnings
RM-ODP: Reference Model of Open Distributed Processing
RPC: Regional Planning Council
RPE: Roadway Payment Equipment
RS: Roadway Subsystem (legacy National ITS Architecture)
RSE: Roadside Equipment
RSI: Road Safety Inspection
RSU: Roadside Unit
RSZW: Reduced Speed Zone Warning
RTCM: Radio Technical Commission for Maritime Services
RTP: Regional Transportation Plan
RTPA: Regional Transportation Planning Agency
RTS: Remote Traveler Support Subsystem (legacy National ITS Architecture)
RV: Remote Vehicle
RVI: Route ID for the Visually Impaired
RWIS: Road Weather Information System
RWMP: Road Weather Management Program