Policy Brief

Transportation Mega-Projects and Risk

What we can learn from Boston's Big Dig to improve future major infrastructure projects

Mega-projects in transportation have been uncommon in the United States for the past two decades, following completion of the Interstate highway system and a shift of emphasis in many metro areas from highways to transit. But two recent trends suggest that mega-projects may soon make a return. The first is a growing recognition that major investments in increased mobility are needed, both to relieve urban traffic congestion and to rebuild and modernize major portions of the Interstate system as they reach the end of their original design life. And the second trend is the growth in infrastructure investment funds, with over $150 billion in equity to invest in projects that can produce a reliable revenue stream (such as toll roads, bridges and tunnels).

But the observer may raise a legitimate concern at this point. What about the inherent risks of multi-billion-dollar projects? Isn’t there a sorry track record of such projects costing far more than initially projected and attracting far fewer users than forecast? There are indeed such risks, and no recent U.S. project exemplifies them better than Boston’s Central Artery/Tunnel project, the first portion of which opened to traffic in 2003, with all portions in operation by 2007. Popularly known as the Big Dig, this project can teach many lessons about risks involved in such mega-projects.