The full Massachusetts Senate on Thursday is expected to debate a five-year transportation borrowing bill that has risen to $13.2 billion.

The bill, which cleared the Senate's Ways and Means Committee on Tuesday, would add $300 million to the House version that passed in late January. The state Department of Transportation's original proposal for its capital improvement plan called for $12.4 billion.

MassDOT's request calls for $3.3 billion to rehabilitate and maintain bridges, including nearly $1.7 billion to finish megaprojects under the accelerated bridge program, an eight-year project that began in 2008. They include the Longfellow Bridge connecting Boston and Cambridge; the Whittier Bridge between Amesbury and Newburyport; and the Braga Bridge that connects Somerset with Fall River.

It also earmarks $1.3 billion to complete the extension of the Massachusetts Bay Transportation Authority's Green Line from Lechmere Square in Cambridge to Somerville and Medford by 2020, though U.S. Rep Michael Capuano, D-Mass., said Wednesday that President Obama has included it in his federal budget proposal.

The extension is an environmental requirement of the Central Artery/Tunnel Project, known commonly as the "Big Dig."

A further $1.5 billion in MassDOT's proposal is for municipal projects, including $200 million per year for road improvements under the state's Chapter 90 program, and $254 million for the South Coast rail project.

Additionally, the bill would rename South Station after former governor and 1988 presidential candidate Michael Dukakis.

Last year's transportation bill generated an estimated $6.4 billion for projects over 10 years, according to Transportation Secretary Richard Davey.

"However, the passage of a comprehensive, multi-year transportation bond bill is now needed to authorize the borrowing and expenditure of funds for critical highway, rail and transit, aeronautics and registry projects throughout the commonwealth," Davey wrote Senate President Therese Murray, D-Plymouth.

Davey said bond bill approval is necessary to proceed with 51 projects valued at $261 million to private sector contractors for which MassDOT's highway division has advertised and rewarded contracts.

In addition, he said, the department is ready to advertise another 76 federal aid program projects valued at $300 million, "but again, we are unable to do so without demonstrating that we have authorization to spend for the state proportional share on those projects."

Delays, Davey added, could also affect rail and transit projects including the procurement of buses and MBTA Red and Orange line trains that will be assembled in Massachusetts.

Moody's Investors Service rates Massachusetts' general obligation bonds Aa1; Fitch Ratings and Standard & Poor's rate them an equivalent AA-plus.

Subscribe Now

Independent and authoritative analysis and perspective for the bond buying industry.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.