The information is merged by TomTom and algorithms are used to improve the data and filter out anomalous readings. The system sends updates to all TomTom Traffic users every two minutes (and the data the users receive is never older than 30 seconds). Users can receive the service through the built-in SIM, via a smartphone connection or on older devices via a standard phone connection. Re-routing can be set to be transparent to the user with the only sign that the route has been changed due to a traffic jam being a sound indication from the device and a changed .