There’s been a lot of attention paid to the state of bridges in the US since the collapse of the I-35W bridge in Minneapolis last week.  However, compared to our dams, sewers, waterway locks, power grid and roads the bridges are actually in pretty good shape.  This is scary stuff, and the slide-rule brigade knows all about it.  While our bridges get a "C" grade from the civil engineers most of our infrastructure seems to be getting a barely passing grade:

• Aviation – D+
• Dams – D
• Drinking Water – D-
• Energy – D
• Hazardous Waste – D
• Navigable Waterways – D-
• Public Parks & Rec – C-
• Rail – C-
• Roads – D
• Schools – D
• Solid Waste – C+
• Transit – D+
• Wastewater – D-
• Roads – D
• Schools – D

I wonder if we’re in this mess because we’re beginning to run into these problems because so much of our infrastructure was built during FDR’s civil works projects of the great depression and the post-war expansion of the 50s and we’re reaching the life expectancy for so many of these engineering projects. Or is it because we haven’t spent enough of our dollars on maintaining and upgrading our infrastructure? Is it because our population is growing too fast for the infrastructure to keep up?  All of the above?