Number of accidents in Big Dig tunnel spurs an investigation

The O'Neill tunnel, part of Interstate 93, is about 1.5 miles long; the older tunnels, which link downtown to East Boston, are about a mile long.

"The Massachusetts Turnpike Authority has launched an evaluation of the accident data and the geometry of the highway and tunnel," authority chief of staff Stephen Collins wrote in a July 20 letter to Zarrilli. "This engineering evaluation includes an assessment of the pavement condition, horizontal and vertical curvature, sight distances, signage, lighting, and all engineering aspects of the roadway and tunnel," Collins wrote.

The letter thanks Zarrilli for his diligence and concern for safety.

"I can assure you that public safety is of utmost concern to the Massachusetts Turnpike Authority and that safety issues identified in the engineering analysis will be appropriately addressed by the Authority," he wrote.

Authority spokesman John Lamontagne said the authority is confident that the Tip O'Neill Tunnel is a safe part of the highway.

"We're constantly evaluating the tunnel to determine if there are ways we can enhance driver safety," Lamontagne said. He declined to comment further.

The tunnel was named for late House Speaker Thomas P. "Tip" O'Neill Jr., one of the political fathers of the Big Dig project. The tunnel carries traffic beneath the city along Interstate 93.

Zarrilli, a longtime civic activist who once proposed an alternative project to the Big Dig, said he wants to see the speed limit in the O'Neill tunnel reduced from 45 miles per hour to 30 miles per hour.

"They can erect signs before one enters the tunnel saying, 'Speed strictly enforced by video monitoring,' " Zarrilli said. "If that signage were to take place, the number of accidents per month would be reduced."

He is pleased that state officials are taking his concerns seriously, Zarrilli said.

"I'll stay right on top of it," he said, referring to his frequent requests for public documents revealing accident data. "The public does deserve to know."