PIKEVILLE, N.C. (AP) A North Carolina Department of Transportation engineer warned officials in 2003 and 2004 that the more than 5 in. (12.7 cm) of asphalt they planned to use on Interstate 795 would be too thin and too weak.
Now, DOT officials are weighing repairs for the highway that could cost between $1.6 million and $10 million.
While officials haven’t determined the extent of or a cause for the pavement failure, they have reached tentative agreement on a remedy — thicker asphalt.
The two-year-old pavement on North Carolina’s newest interstate is deeply fractured in some places. Core samples of asphalt cracked apart Feb. 7 when test lab engineers pulled them out and laid them gently on the roadway.
Cracks and potholes began appearing just 16 months after traffic started rolling down the new four-lane freeway between I-95 at Wilson and U.S. 70 at Goldsboro. The asphalt was expected to bear cars and trucks for 15 years.
Wendi Johnson has overseen road construction for DOT Division 4 in Wayne and five other counties for the past eight years. She has seen other new roads that needed pavement repair years earlier than expected, including U.S. 64 near Rocky Mount and U.S. 264 near Wilson because the original asphalt wasn’t thick enough.
The division has had failure of pavement in the past with the thin design, Johnson wrote from her Wilson office on Aug. 23, 2003, to Clark Morrison, who heads the DOT’s pavement design unit in Raleigh.
It would be cheaper to add sufficient pavement while the freeway was being built than to come back later for big repairs, she said.
Her plea for three more inches of asphalt on 17 mi. (27.4 km) of I-795 would have added $2.8 million to the project’s $196 million pricetag, but DOT officials said it was too expensive. They said the thinner design would suffice for a freeway projected by 2024 to carry 40,800 cars and trucks each day.
Johnson watched Feb. 7 as engineers from two DOT labs drilled 4-in. (10.1 cm) and 6-in. (15.2 cm) core samples and lifted 24-sq.-ft. (2.2 sq m) asphalt slabs out of the roadway.
Last year, the department spent $22.4 million to rip out a 3-in. (7.6 cm) layer of almost-new concrete — four lanes wide and 10.4 mi. (16.7 km) long — on I-40 in Durham County. Mistakes in design and lapses in construction oversight were blamed for a botched paving job that caused the new concrete to deteriorate.
The I-40 mistakes led to the resignation of the DOT’s chief roadbuilder. It helped spark a $3.6 million initiative that is supposed to make the DOT a more efficient, businesslike and accountable agency.
Judith Corley-Lay, DOT’s chief pavement engineer, told Johnson in a Dec. 6 memo that months of tests had pointed to a fix for the problem on I-795 but not to its cause. She recommended replacing 2.5 in. (6.4 cm) of damaged asphalt along about 2.8 mi. (4.5 km) of I-795 near Pikeville, and topping it with another 1.5 in. (3.8 cm), for $1.6 million.
“While these analyses do not answer the question of exactly what failed this pavement, it does demonstrate that additional quality thickness is needed,” Corley-Lay wrote.
Johnson’s former boss was less guarded in his assessment of the I-795 pavement failure.
“It was preventable, absolutely,” Jim Trogdon, who was DOT’s supervising engineer for Division 4 until 2005, said in an interview.
Trogdon said DOT did not really save money when it rejected Johnson’s recommendation to spend $2.8 million for more asphalt.
“It’s a false savings if you have to come back later and do substantial repairs after you open it to traffic,” Trogdon said.