Bing Maps shows users current traffic information for major highways and roads. The feature uses 4 color codes (black, red, yellow, green) to indicate traffic volume, from heaviest traffic to lightest traffic. Microsoft announced in March 2008 that it will release its latest software technology called "ClearFlow". [needs update] It is a Web-based service for traffic-based driving directions available on Bing. com in 72 cities across the U. S. The tool took five years for Microsoft's Artificial Intelligence team to develop. ClearFlow provides real-time traffic data to help drivers avoid traffic congestion. ClearFlow gives information for alternative routes and supplies traffic conditions on city streets adjacent to highways. Clearflow anticipates traffic patterns, while taking into account sporting/arena events, time of day and weather conditions, and then reflects the back ups and their consequential spill over onto city streets. Often, ClearFlow found it may be faster to stay on the highway instead of seeking alternative side street routes, which involve traffic lights and congestion as well.