Today Microsoft announced a new feature on its Live Search Maps service: Clearflow, an option that will alter driving directions based on traffic, not just on the usually metered major freeways, but on adjoining connector ramps and streets as well. See news story.
I find the Clearflow product of only marginal usefulness on a PC, since traffic patterns change quickly. I'd trust it to get me on to a freeway in the most efficient way, but if my route takes more than 20 minutes, I'd worry about its accuracy at the other end. If this technology can be applied to Microsoft's Live Search Mobile, and if it can update the route in real-time when conditions change, then it will be killer.
But I digress. The technology development effort to predict traffic flow on unmetered roadways was led by Microsoft's Eric Horvitz. What's interesting is that Horvitz et al. also developed another traffic prediction system, which was spun out to the company Inrix (previous story), which in turn sells its data back to Microsoft.
Inrix collects traffic-flow data directly from vehicles (mostly the GPS units in trucks and other commercial vehicles, but also some mobile phones and Dash Navigation units). Based on the historical data it collects, it can predict traffic on the routes it has coverage for.
Inrix does not do the routing itself, but it supplies its data to Microsoft (and other mapping companies, auto manufacturers, and GPS device makers) who then can incorporate it into their routing algorithms. Microsoft's new Clearflow prediction system doesn't overlap much with Inrix's prediction algorithm, since Clearflow predicts what the traffic of the moment will be on unmetered streets, while Inrix provides data for all highways, and predicts traffic flow in the future.
Since Inrix collects data from actual moving vehicles, not just road sensors, it can report on traffic speeds on any road where there are drivers. Today, the company announced that it's now providing coverage on all U.S. freeways, for instance--over 100,000 miles of roads. Mapquest will be the first of Inrix's customers to use that data in its direction-finding service.
What's next in traffic routing? Inrix CEO Bryan Mistele says the "Holy Grail" is routing based on the routes real drivers take, not just observed speeds. For example, a navigation service could record the actual paths people take between points, and use this data as well speed information to generate directions. Of course, there are privacy implications when you're recording users' driving in this way, but there's all that data to be got from commercial vehicles. So in the future, the wisdom of taxi drivers may end up popping up on our in-car GPS gizmos.