TomTom uses multiple up-to-the-minute sources to determine the speed of a traffic jam.
Data from Vodafone's GSM network. Vodafone knows when and wheretelephones are linked to a mast and where they are moving. Thisinformation is anonymised and sent to TomTom. TomTom uses thisinformation to calculate the speed with which every telephone in a caris moving. In the case of traffic jams, cars move more slowly and thusthe telephones move more slowly too.
Data from TomTom users. Certain TomTom devices send anonymousinformation about their location and speed once the user has givenpermission to do so. Certainly when information from many differentusers is combined, this results in reliable traffic jam information.
Data from third parties such as national and local governments and commercial traffic information providers.
TomTom combines these sources to produce a reliable estimate。