What is this blog about?

We are destroying the planet at an alarming rate. It's happening due to the ignorance of the world we live in, and in our age of online data access and sharing there is really no excuse for that any more.

This blog investigates novel ways of looking at large datasets. The kind everyone should care about.


This is my personal blog. The views expressed on these pages are mine alone and not those of my employer.

Saturday, October 4, 2008

State percentages of deficient/obsolete bridges

To follow up on the previous post, I wanted to plot some aggregate data on bridge conditions. US DOT provides per-state statistics for the total number of bridges, as well as the percentage of structurally deficient and functionally obsolete bridges.

According to the official explanation, "structurally deficient" in most cases means that deck, superstructure or substructure has a rating of 4 or below. "Functionally obsolete" means that the bridge does not pass the current standards for road width or roadway alignment. An appraisal rating of 3 or below puts bridge in this category.

Here is the map (click here to access it directly)



The default view shows only the structurally deficient bridges. Click on the eye icons in the upper right corner to turn layers on and off.

Northeast is not doing so well on obsolete bridges - DC and Massachussetts are the leaders with 52% and 40%. This could be explained by the sheer number of old bridges, I suppose.

For structurally deficient bridges, Pennsylvania and Oklahoma lead the way with 26 and 25%. Note that to highlight differences, I chose slightly different algorithms for calculating icon sizes on the two layers.