As economic uncertainty swirls around the Capitol Hill debt limit negotiations, some Top 400 contractors are worried about reaching the limit of their ability to keep projects profitable.

The market has hit its tenth year of growth, one of the longer expansions in history. But firms don’t see any signs of a cooling off.

Large contractors know it can’t last, but right now the market continues to expand, and few firms see any clear signs of a slowdown.

Manufacturers are demanding process efficiencies, lean construction, highly collaborative and flexible spaces, prefabrication and even more complex automation that makes for more difficult projects for their general contractors and construction managers.

Water and wastewater construction revenue in the U.S. appeared to shrink last year, as measured by reports from the ENR Top 400 Contractors. But new needs and supply approaches are creating opportunities for firms.

Contractors say they expect the demand for petroleum—liquefied natural gas (LNG) and petrochemicals production, in particular—will remain strong across the U.S. in the near future, with capital markets and construction projects following suit.

Contractors are embracing new technologies to help reduce costs for traditional and renewable electricity generation as the industry continues to build, almost exclusively, natural gas, solar and wind power plants.

Despite ongoing uncertainty regarding federal funding promises, there is no shortage of opportunities in all sectors of U.S. transportation.