When infrastructure projects are subject to political involvement, cronyism ensues as interest groups and factions lobby for the limited available resources. Resources are not primarily allocated based on a real return on investment, but according to political preference and expedience. The result is that too much is spent in certain areas and too little in others. “Too much” includes bridges to nowhere, high-speed trains and public transportation projects without sufficient ridership, freeways in sparsely populated areas, subsidized wind- and solar farms, etc. “Too little” includes the nation’s energy grid, hydro-electric dams, and nuclear power plants, which either don’t score the necessary political points or are outright opposed by both politicians and the pressure groups they’re in bed with.
Misallocation may also hurt certain areas while benefitting others. For example, the interstate system being “free” (the cost is not directly charged to the users in the form of road tolls but tax- and debt-financed) almost killed the nation’s railroads as both passenger and goods transportation migrated to the subsidized U.S. interstates and highways (railroad regulations played a significant role as well).
Finally, due to the lack of long-term thinking among politicians as discussed in the natural disaster section, infrastructure maintenance is often neglected as having less of a political draw than the new and shiny.
Think Right or Wrong, Not Left or Right 