So what is the primary lesson of the St. Anthony Bridge (I-35W bridge in Minneapolis, see photo above) rebuild? Private enterprise works. Most road and bridge construction in America gets performed by state agencies who subcontract bits and pieces out while retaining the general-contractor role. In this case, the bridge replacement was so badly needed that Minnesota dumped that model to use one that would produce a bridge in a shorter period of time — and incentivized the contractor to get it done fast.
Private enterprise works. Businesses understand this. When they need project work done, especially for projects where speed is essential and the work outside the scope of their expertise, they hire contractors to do it rather than hire the expertise onto their own payrolls. Contractors who fall behind can be penalized or even replaced without having to worry about employment law and other administrative headaches. They can also get bonuses without invoking other kinds of payroll issues.
Related 1: "5 Engineering Lessons From the New, Reopened Minnesota Bridge" in Popular Mechanics
Related 2: As economist Steven Landsburg reminds us, "Most of economics can be summarized in just four words: People respond to incentives. The rest is commentary."