Michigan's ageing bridges

The US state of Michigan needs to invest in highway bridge repairs. A report by 2770 Transportation for America says that in excess of 13% of the state's highway bridges are structurally deficient, compared with an average of 11.5% across the US. The problem is likely to increase according to the report as bridges age and come closer to their planned 50 year lifespan. Up to 1,400 bridges in Michigan are structurally deficient according to federal standards. In all Michigan has 11,000 road bridges and they are 41 years old on average. In the US, about 185,000 bridges are more than 50 years old and the number could double by 2030. Transportation for America says one in nine US bridges are in poor condition, while it would cost US$71 billion to improve the condition of its structurally deficient bridges.