ITIS sources traffic information from various fleet management companies, whose vehicles provide thousands of location reports to the ITIS Floating Vehicle Data system (FVD®). This information, together with location information from tens of thousands of other vehicles, is stored in the world's largest operational floating vehicle data warehouse.

This data warehouse, when combined with journalistic incident information, supplies ITIS' TAG system with the data needed by ITIS' archive, internet and short dial telephone information products, as well as iTMC, the UK's only national RDS-TMC service.