A firm hired to do inspection services on a botched $44.8-million concrete paving job in North Carolina is denying any role in the problems that led to potholes and crumbling on Interstate 40 in 2005. The newly paved 10.6-mile stretch between Raleigh and Durham needs at least $18.6 million in repairs. Contractor Granite Construction, Watsonville, Calif., accepted no blame but agreed to contribute $3 million to the fix. Inspection services provider HNTB Corp. does not plan to contribute.

In 1999, the North Carolina Dept. of Transportation opted to bond a 3-in. layer of concrete to the existing surface. Full-depth transverse joints must be cut into the overlay to prevent compression-related failure. But the design failed to specify cut depths for the joints, according to a report issued late last year by state Secretary of Transportation Lyndo Tippett. Subcontractors cut the overlay at depths from 1.5  to 3 in.

Tippett largely blames DOT personnel and notes that the Federal Highway Administration reviewed the plans but failed to catch the error. He also faults Kansas City-based HNTB for not catching the oversight. NCDOT declined to comment, but the report states that NCDOT “is proceeding to take action to hold [HNTB] accountable for their share of the project failure.”

But HNTB only provided inspectors to work for NCDOT, says Henry Liles, HNTB’s area vice president. “HNTB had no responsibility for management of those people. We never looked at the design because it was not part of our contract.” The DOT could have refused any of the candidates, he adds.

FHWA will fund about $14 million for repairs. Several NCDOT engineers were issued “written warnings.” NCDOT is reconsidering the use of private firms for “traditional agency roles.”  It will require senior managers to do more site visits, use pavement performance warranties and do more rigorous reviews of new project techniques.