Sections of Central Artery pavement that were supposed to last 30 years are failing in less than a decade, causing a rash of potholes and debris at the mouth of the Thomas P. O’Neill Jr. Tunnel and at other key points and forcing $1 million in unexpected repairs, the state’s top highway official said Wednesday.
Highway maintenance crews have been filling potholes as they appear, including rare midday work last week to repair a 4-foot-square flaw that could have posed a rush-hour hazard, said Frank DePaola, the state’s highway administrator. But the potholes are now frequent and extensive enough that entire sections must be repaved, causing temporary lane closures.
The problem stems from a decision by the Bechtel/Parsons Brinckerhoff team that oversaw Big Dig design and construction to pave the project with concrete, more commonly used in warmer climates, instead of traditional New England asphalt, DePaola said. That surface concrete is now separating from the structural concrete slabs below it wherever the highway has a steep slope, such as at on- and offramps and tunnel openings, he said.
“They recommended it on the steep slopes because they thought it would be more durable,’’ DePaola said after informing the state Department of Transportation board that the most crumbling stretch - a 600-foot-long section where Interstate 93 northbound leaves the O’Neill Tunnel and climbs the Leonard P. Zakim Bunker Hill Memorial Bridge - would be repaved later this month.
DePaola said the problem is a surface issue, not a structural or safety matter, but it represents the latest flaw in a $15 billion project that changed the face of Boston and has been plagued with high-profile problems.
“It’s an unfortunate symptom of this project that some of the finishes were possibly not done at as high a quality as they could have been,’’ DePaola said.
The initial work at the northbound start of the Zakim, expected to cost $200,000, will be conducted overnight on select weekends over the next few weeks and will result in temporary lane closures when crews are milling and repaving, said DePaola. Other problem areas will be addressed next year.
The repaving may be eligible for reimbursement through a maintenance trust set up in 2008 with proceeds from a nearly $500 million settlement with Big Dig contractors Bechtel/Parsons Brinckerhoff and others for shoddy work, ranging from water leaks to a ceiling-tile collapse that lead to a fatal accident in 2006.
DePaola informed the board of the pavement issue at a wide-ranging meeting in which board members grilled the chief executive of a South Korean company that has fallen behind on a $190 million order for MBTA commuter rail coaches; approved an overdue $112 million overhaul for deteriorated 1980s Green Line trolleys; and set in motion changes intended to control escalating costs on The Ride, the T’s door-to-door service for people with disabilities.
The five-member board, which also oversees the MBTA, spent 45 minutes asking questions and demanding improvements from the chief executive of Hyundai Rotem, which has fallen nearly two years behind, and possibly more, on an order for 75 double-decker rail cars.
“If you want to continue to have a reputation in this country, then you fix this,’’ board member Janice Loux said. “You fix this or we will fire you.’’
Chief executive Min-ho Lee, speaking through a translator, vowed to redouble efforts at the company’s headquarters in Korea, where the coaches have been designed and the shells are being built, and at the Philadelphia plant slated to perform final assembly.
“We have come to the United States to tell you that we are prepared to bear additional costs in order to use all of the resources at our disposal to ensure that we are able to deliver high-quality vehicles to you as quickly as possible,’’ Lee said.
Board members and Secretary of Transportation Richard A. Davey said they appreciated Lee’s visit but will remain frustrated until they see a redrawn schedule and actual production. “Optimism is good, but it doesn’t deliver cars,’’ Davey said.
The meeting was the board’s last before a scheduled MBTA fare increase hits July 1, with fares and passes increasing an average of 23 percent, including a 30 cents on CharlieCard subway fares and 25 cents on CharlieCard bus fares.
The increase will be much higher for The Ride, which is scheduled to double from $2 to $4 one-way and rise to $5 for customers traveling in a new “premium service’’ area. That plan has drawn sharp criticism from people with disabilities who say it will leave those on a fixed income homebound and that the changes to the map have been poorly articulated.
In response, Jonathan R. Davis, the T’s acting general manager, said the $5 premium pricing area would not begin until Oct. 1, though the $2 to $4 increase will still occur July 1.
Escalating popularity has driven the annual cost of The Ride above $100 million; it now consumes nearly 10 percent of the T’s operating budget, while accounting for less than 1 percent of all MBTA trips.
To discourage possible abuse, the board Wednesday authorized the T to sign a contract worth up to $10 million to create an in-person assessment program to evaluate Ride candidates, who currently qualify by submitting a note from their doctor.
The changes will begin in the fall for new applicants and next year for renewing Ride users, T spokesman Joe Pesaturo said.
The board had balked repeatedly at staff requests this year to approve a contract with Innovative Paradigms of California, heeding criticism from disabled customers who said the selection process did not sufficiently consider public input and warned that the assessments might discourage genuinely qualified Ride customers who are reluctant to be examined in an MBTA office.
“I would ask us to think about our own sense of social justice,’’ said board member Elizabeth Levin, worried that the evaluation process would scare off some who need The Ride.
The board voted to approve the deal with conditions - that the T carefully monitor the assessment process and retain the right to modify it based on public input without the consent of Innovative Paradigms.
John Winske, a disability-rights activist from Boston, said he had hoped they would instead reject it and start over. “We know sooner or later they have to do in-person assessments, but it’s a lot better to work with the community and get their feedback than to ram it down people’s throats,’’ said Winske, of the Disability Policy Consortium.