Quantity growth claims continue in design-build | Why sweltering Phoenix is still growing | Reinventing tunneling tech with robot swarms

Contractor claims against their designers for quantity growth in standard design-build are once again in the news this summer.

Part of the world's mega-project moment is a shift to more collaborative contracting models, including an increase in progressive design-build and even talk of alliance contracting models coming to North America. But a new lawsuit on Boston's Green Line Extension project (which just opened in December of 2022) underscores why claims on standard design-build jobs are unlikely to disappear completely.

So how should contractors and their designers protect themselves from potential cost overruns on these types of projects, particularly "horizontal" transit and highway jobs? The potential solutions are a blend of technical, commercial, and contractual mitigation techniques.