Regionator scores data by a user-specified metric and arranges placemarks into KML regions so that only highest-scoring ones are shown at high zoom levels. The placemark size corresponds to the amount of daily traffic, and the color shows the bridge rating. Placemark description provides data about the bridges: names, detailed condition and appraisal ratings, year built, daily traffic and the name of the agency responsible for maintenance. Here's a sample image.
This might be of interest to people who work with presenting large datasets online, as well as to those who are curious about the condition of their local bridges. Let me know if you have any suggestions on improving the visualization or on ways to make the underlying data available to other tools."