States are committing more American Recovery and Reinvestment Act highway funds to specific projects, and pavement improvements continue to get the largest share of those dollars. But the mix of ARRA-funded highway work is shifting a little, to more complex projects, the Government Accountability Office reports. Total federal ARRA highway outlays—reimbursements to states—also still lag well below obligations.

GAO’s latest ARRA update, released on Sept. 23, shows states had obligated nearly $18 billion of $26.7 billion in ARRA highway aid by Sept. 1. That is a 7% gain from $16.8 billion obligated by July 17.

The top ARRA highway category remains pavement improvement or widening, which received $11.7 billion, or 65% of total highway obligations. GAO notes many state transportation departments emphasized pavement projects because they could be bid rapidly and finished in three years. New road construction was allotted for $1.1 billion, or 6% of the total. Bridge replacement or new bridge construction funding was $1.2 billion, or 7%.

The overall pavement-project percentage is down slightly, from 66% as of July 17. GAO notes that it “found states are beginning to select projects entailing more complexity.” Massachusetts, it says, is starting to choose “more complicated construction and reconstruction projects,” such as a $36-million pedestrian bridge.

GAO notes that states’ use of ARRA highway aid varies widely. Ohio has obligated 37% of its ARRA highway funds for new road or bridge construction and Florida has earmarked 21% of its ARRA allocation to those categories, well above the 8% national average. Iowa and Massachusetts have focused much more heavily on pavement improvements, each obligating 85% of ARRA highway allocations for such projects.

Competition is driving down bid prices, GAO says. In Arizona, lower-than-anticipated bids saved $60 million. In Colorado, bids for 32 of 41 awarded ARRA projects were below engineers’ estimates, saving $39 million. As a result, the states say they will fund more projects.

Federal reimbursements to states are up sharply since June 25, but still are only $1.4 billion.