TA: Tailgating Advisory, Threat Arbitration
TAS: Toll Administration Subsystem (legacy National ITS Architecture)
TBD: To Be Determined
TC: Technical Committee
TC: Target Classification
TCDs: Traffic Control Devices
TCIP: Transit Communications Interface Profiles
T-CONNECT: Transit Connection Protection
TCP: Transport Control Protocol
TCP/IP: Transport Control Protocol / Internet Protocol
TCS: Toll Collection Subsystem (legacy National ITS Architecture)
TD: Transportation Disadvantaged
T-DISP: Transit Dispatch
TDM: Travel Demand Management
TEA: Transportation Equity Act
TEA-21: Transportation Equity Act for the 21st Century
TIA: Telecommunications Industry Association
TIC: Transportation Information Center
TIP: Transportation Improvement Program
TLS: Transport Layer Security
TM: Traffic Management
TMA: Transportation Management Area
TMC: Traffic Management Center
TMDD: Traffic Management Data Dictionary
TMS: Traffic Management Subsystem (legacy National ITS Architecture)
TNC: Transportation Network Company
TOC: Traffic Operations Center
TOIP: Traffic Operations Infrastructure Plan
TPA: Transportation Planning Authority
TRB: Transportation Research Board
TRMC: Transit Management Center
TRMS: Transit Management Subsystem (legacy National ITS Architecture)
TRV: Transit Vehicle
TRVS: Transit Vehicle Subsystem (legacy National ITS Architecture)
TS: Time Synchronization
TSA: Transportation Security Administration
TSE: Traveler Support Equipment
TSMO: Transportation Systems Management and Operations
TSP: Transit Signal Priority
TSR: Transit Stop Request
TTI: Texas A&M Transportation Institute
TVCW: Transit Vehicle Crash Warning
TVSSW: Transit Vehicle at Station/Stop Warnings