Where does My Commute in Nokia Drive retrieve the traffic info from? - Nokia FAQ
The traffic info for My Commute is collected from various sources:
Incident reports: Incidents range from jams on highways to planned construction works. These reports come often from local authorities such as the police or a local traffic management central. In many areas we have partnerships with the local authorities who will send the information to us.
Highway sensors: Many metropolitan areas have statically installed traffic flow sensors that measure the current average speeds on highways and major roads.
Crowd-sourcing: While the incident reports are very punctual and the installed sensors usually focused on major highways, we are also using the wisdom of the crowd to understand the traffic situation over the whole city. These are for example Nokia smartphones running Nokia Drive. People who are consuming traffic information can also improve the service by providing anonymous information about their current travel speed.
Historic information: The above information is archived and assumptions are made about the current speed on a street based on the historic information if there's not enough information from sensors or probes. Many streets in a city have a very regular pattern, e.g. the same traffic jam every morning but fast during night times.
Modelling: In many cases the traffic situation on the whole street network can be deducted from partial information. E.g. from a heavy jam on a highway one can often deduct the situation on the slip road entering the highway as well as the streets just before that.