Elevated Massachusetts Turnpike between BU and Charles River with Soldiers Field Road at grade. The bend in the Turnpike at the top of the picture would be straightened if the broader project I-90 Allston interchange project is pursued. Massachusetts Department of Transportation.

The Massachusetts Department of Transportation now says it plans to include $243 million for the $1.9 billion I-90 Allston project in the agency’s next five-year capital investment plan, and offered a vague explanation for why the money was not included last month in the original draft of the spending plan.

“This additional funding was not originally included in the CIP while MassDOT continued to work on the detailed financing plan. The timing of cash flows on the project is still subject to change,” said a statement issued by Amelia Aubourg, the chief communications officer at MassDOT.

MassDOT officials also said the money for the I-90 Allston project was included because of input during the public comment period on the capital investment plan, which runs from fiscal 2025 through fiscal 2029. The officials said such changes are not unusual.

The explanations left many observers scratching their heads, and some wondering whether the MassDOT staff simply forgot to include funding in the capital investment plan for one of the Healey administration’s highest transportation priorities and a project that has already secured a $335 million federal grant.

Aubourg’s statement that the money was not included in the original capital investment plan because a detailed financing plan for the project wasn’t complete also didn’t add up. The capital investment plan included $772 million in funding to begin replacing the Cape Cod bridges even though a detailed financing plan for that massive project isn’t finished.

Supporters of the I-90 Allston project – which would straighten and lower to ground level the Massachusetts Turnpike as it moves through Allston, making way for the development of a new neighborhood by Harvard University – were just happy that money for the project was added in. None would talk about the funding reversal on the record.

Michelle Scott, MassDOT’s capital planning director, revealed initial construction funding for the I-90 Allston project had been included in the capital investment plan during briefings she delivered on Tuesday to two subcommittees of the full board. She said the $243 million would go for project design and design-build spending. An additional $62 million in seed money for design work on the project was included earlier, bringing the total to nearly $306 million.

“We do want to take this opportunity to reflect commitments to the project in the CIP,” Scott said, providing no explanation for why the funding wasn’t included before.

Interestingly, none of the MassDOT board members questioned her about the about-face. Even Richard Dimino, who got into a tiff with Transportation Secretary Monica Tibbits-Nutt at a June board meeting over the lack of construction funding for the I-90 project, didn’t seek any answers. He did not return phone calls afterward.

At the June board meeting, Dimino, a strong supporter of I-90 Allston, sought to have the board go on record in support of including construction funding for the project in the capital investment plan to signal to the Federal Highway Administration that the state is serious in moving forward. Dimino suggested the lack of funding in the plan had been an oversight.

“I don’t want this to be characterized as an oversight by our staff because it wasn’t,” said Monica Tibbits-Nutt, the state secretary of transportation.

“We’ll agree to disagree on this particular matter,” Dimino responded.

Tibbits-Nutt then suggested she ordered staff to not include money in the capital investment plan for the final design and initial construction of the project. “The staff did an excellent job at the direction of me. It was not an oversight,” she said. Her office provided no additional explanation at the time.

Scott indicated the $243 million would come partly from the $335 million federal grant the state has received for the project and partly from toll revenues from the Tobin Bridge, the Turnpike inside Route 128, and the Sumner, Callahan, and O’Neill Tunnels.

The state is also counting on at least $300 million from the city of Boston, Harvard University, and Boston University.  The remaining funding is expected to come from the state, but details haven’t been announced yet.

Bruce Mohl oversees the production of content and edits reports, along with carrying out his own reporting with a particular focus on transportation, energy, and climate issues. He previously worked...