Samenvatting
The Automobile Association (AA) operates a high quality traffic information service, "Roadwatch", across the entire road network of Great Britain. In providing this service, over 400,000 different congestion reports are received each year. This paper reports on how this congestion data has been analysed to show trends in congestion, particularly focusing on how major events such as the Solar Eclipse in August 1999 affected the traffic throughout the UK.