BY DAVE PARRO
An analysis done by The Associated Press of Illinois' 2,400 bridges rated as "structurally deficient" by the federal government shows that 1,500 of them received lower ratings on a 100-point scale than the Minnesota crossing that collapsed last month, killing 13 people. That's a scary thought.
Nine of those bridges are located in this area. Fortunately, two of them have been rehabbed since the U.S. Department of Transportation collected the data, and one is closed. The other six are scheduled for reconstruction by 2010.
The worst of them is the state-owned Route 25 bridge over Waubansee Creek near Oswego. That bridge received a score of 2 out of 100, tied for second-worst in the state.
The ratings, however, are complicated and might not always directly reflect the dangers posed by these troubled bridges.
Here's a look at the bridges in our counties that are considered deficient because they failed in one or more areas.
The AP explains the two rating systems this way:
A 9-point scale is used to rate the condition of key areas. A rating below 5 is considered from poor to failed condition, while 5 and above is fair to excellent. Bridges that do badly in one or more of these categories can be declared “structurally deficient.”Bridges that receive an 80 or lower on the 100-point scale qualify for federal repair money, while those at 50 or below could get money for replacement.
The nine local bridges that ranked lower than the Minnesota crossing, which had a rating of 50, did so on the 100-point scale, which reflects their structural integrity as well as other factors such as design. A bridge with decent structural ratings, for example, could still receive a low overall rating because its design is obsolete.
What's obvious from looking at the database is that the major bridges might not be the ones most likely to collapse. The rural structures that carry less traffic actually seem to be in the worst shape. That means fewer people are at risk, but also that they could be more easily overlooked.
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