US 2007 bridge condition data

I have taken the 2007 bridge inspection data from Federal Highway Administration, US Department of Transportation and converted into KML. Since that's a lot of information, it's not shown all at the same time. Rather, I use a KML feature called "regions".

When the map view is zoomed very far out so that you see whole countries and continents, only a small subset of regionated data will be visible, to avoid clutter. In this case, bridge rating provides a scoring metric, so only the most critical bridges are shown at first. As the view zooms in, more and more bridges will appear until you see all available data for the small piece of the map you are looking at.

The map is only showing the bridges with the lowest condition ratings. Out of total 716,000 bridges, 189,000 bridges, or 26%, are shown. A bridge is shown if its worst condition rating is 5 or less. The ratings go from 0 to 10 for each of several bridge components that are independent from each other(see a separate post for details).

Disclaimer: Federal Highway Administration (FHWA) does not approve, endorse, or recommend this project.

Click here to open the visualization in Google Earth. If you don't have Google Earth, download it. If you have Google Earth plugin installed, scroll down to see the embedded view. Otherwise, here's a sample picture.

This was implemented using regionator - a free, open-source program that converts spreadsheets in CSV format into KML files. Feel free to contact me if you would like to know details or learn to do this yourself.

Each bridge is represented by a circle. Click on any of them to open a description balloon. It will show the road names, daily traffic count, bar charts with specific ratings, the year bridge was built and organization responsible for maintenance. All of these were taken from the original data (and dozens of other fields are available). Unfortunately, bridges are sometimes not located precisely where they should be - they could be several hundred feet or more off (some are in Iceland!).

Circle size shows the amount of daily traffic, and circle color shows what the condition of a bridge is:

Rating	0 (broken)	1 (closed)	2 (critical)	3 (serious)	4 (poor)	5 (fair)
Color	Black	Black	Red	Pink	Orange	Yellow

Bridge rating explanations

This is the explanation of the 2007 US DOT bridge safety data (taken from their document). See main post for a general introduction.


Page 38: ratings for deck, superstructure and substructure (items 58, 59, 60).

Code	Description
9	EXCELLENT CONDITION
8	VERY GOOD CONDITION ‑ no problems noted.
7	GOOD CONDITION ‑ some minor problems.
6	SATISFACTORY CONDITION ‑ structural elements show some minor deterioration.
5	FAIR CONDITION ‑ all primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
4	POOR CONDITION ‑ advanced section loss, deterioration, spalling or scour.
3	SERIOUS CONDITION ‑ loss of section, deterioration, spalling or scour have seriously affected primary structural components. Local failures are possible. Fatigue cracks in steel or shear cracks in concrete may be present.
2	CRITICAL CONDITION ‑ advanced deterioration of primary structural elements. Fatigue cracks in steel or shear cracks in concrete may be present or scour may have removed substructure support. Unless closely monitored it may be necessary to close the bridge until corrective action is taken.
1	"IMMINENT" FAILURE CONDITION ‑ major deterioration or section loss present in critical structural components or obvious vertical or horizontal movement affecting structure stability. Bridge is closed to traffic but corrective action may put back in light service
0	FAILED CONDITION ‑ out of service ‑ beyond corrective action

Page 40: ratings for channel and channel protection (item 61).

Code	Description
9	There are no noticeable or noteworthy deficiencies which affect the condition of the channel.
8	Banks are protected or well vegetated. River control devices such as spur dikes and embankment protection are not required or are in a stable condition.
7	Bank protection is in need of minor repairs. River control devices and embankment protection have a little minor damage. Banks and/or channel have minor amounts of drift.
6	Bank is beginning to slump. River control devices and embankment protection have widespread minor damage. There is minor stream bed movement evident. Debris is restricting the channel slightly.
5	Bank protection is being eroded. River control devices and/or embankment have major damage. Trees and brush restrict the channel.
4	Bank and embankment protection is severely undermined. River control devices have severe damage. Large deposits of debris are in the channel.
3	Bank protection has failed. River control devices have been destroyed. Stream bed aggradation, degradation or lateral movement has changed the channel to now threaten the bridge and/or approach roadway.
2	The channel has changed to the extent the bridge is near a state of collapse.
1	Bridge closed because of channel failure. Corrective action may put back in light service.
0	Bridge closed because of channel failure. Replacement necessary.

Page 41: ratings for culverts (item 62)

Code	Description
9	No deficiencies.
8	No noticeable or noteworthy deficiencies which affect the condition of the culvert. Insignificant scrape marks caused by drift.
7	Shrinkage cracks, light scaling, and insignificant spalling which does not expose reinforcing steel. Insignificant damage caused by drift with no misalignment and not requiring corrective action. Some minor scouring has occurred near curtain walls, wingwalls, or pipes. Metal culverts have a smooth symmetrical curvature with superficial corrosion and no pitting.
6	Deterioration or initial disintegration, minor chloride contamination, cracking with some leaching, or spalls on concrete or masonry walls and slabs. Local minor scouring at curtain walls, wingwalls, or pipes. Metal culverts have a smooth curvature, non-symmetrical shape, significant corrosion or moderate pitting.
5	Moderate to major deterioration or disintegration, extensive cracking and leaching, or spalls on concrete or masonry walls and slabs. Minor settlement or misalignment. Noticeable scouring or erosion at curtain walls, wingwalls, or pipes. Metal culverts have significant distortion and deflection in one section, significant corrosion or deep pitting.
4	Large spalls, heavy scaling, wide cracks, considerable efflorescence, or opened construction joint permitting loss of backfill. Considerable settlement or misalignment. Considerable scouring or erosion at curtain walls, wingwalls or pipes. Metal culverts have significant distortion and deflection throughout, extensive corrosion or deep pitting.
3	Any condition described in Code 4 but which is excessive in scope. Severe movement or differential settlement of the segments, or loss of fill. Holes may exist in walls or slabs. Integral wingwalls nearly severed from culvert. Severe scour or erosion at curtain walls, wingwalls or pipes. Metal culverts have extreme distortion and deflection in one section, extensive corrosion, or deep pitting with scattered perforations.
2	Integral wingwalls collapsed, severe settlement of roadway due to loss of fill. Section of culvert may have failed and can no longer support embankment. Complete undermining at curtain walls and pipes. Corrective action required to maintain traffic. Metal culverts have extreme distortion and deflection throughout with extensive perforations due to corrosion.
1	Bridge closed. Corrective action may put back in light service.
0	Bridge closed. Replacement necessary.

Page 45: comparison with modern criteria (items 67-72)

Code	Description
9	Superior to present desirable criteria
8	Equal to present desirable criteria
7	Better than present minimum criteria
6	Equal to present minimum criteria
5	Somewhat better than minimum adequacy to tolerate being left in place as-is
4	Meets minimum tolerable limits to be left in place as is
3	Basically intolerable requiring high priority of corrective action
2	Basically intolerable requiring high priority of replacement
1	This value of rating code not used
0	Bridge closed