TRANSPORTATION SECRETARY STEPHANIE POLLACK believes the computer model the state uses to predict future transit ridership is unreliable, at least for projects like the proposed West Station in the Allston area of  Boston.

In a recent presentation to a group of stakeholders involved with the planning process for a massive highway and transit project in the Allston-Brighton area, Pollack signaled she agreed with the group’s skepticism about the model, which is named after the organization that runs it, the Central Transportation Planning Staff, or CTPS.

The state is preparing to replace a deteriorating, elevated section of the Massachusetts Turnpike located between Boston University and the Charles River, straighten the Turnpike as it runs through the Allston area, and build a new transit station there called West Station. Much of the land on which the work will be done is owned by Harvard University, which is in the early stages of building a new neighborhood in the area.

In a draft environmental impact report issued in December, the state called for putting off the construction of West Station until around 2040 because of lack of demand. The report, relying on the CTPS model, forecasted 250 commuter rail riders and 2,900 bus riders by 2040.

Pollack has acknowledged the computer model isn’t perfect, but she has characterized it as the only model the state has. In the June 27 presentation to the stakeholders, which was captured on video, she indicated the model was not predicting rider demand accurately for West Station but was nonetheless required for any project seeking federal funding.

“We get that people did not feel that the transit demand analysis we did was credible. We get that you did not like our CTPS model,” she told the stakeholders. “If you know me, you know I don’t much like our CTPS model, either. But when we want federal funding we have to run that model.”

She said the CTPS model was instrumental in landing $1 billion in federal funding for the Green Line extension into Medford and Somerville. The model, she said, also convinced Gov. Charlie Baker that extending commuter rail service to Fall River and New Bedford made sense.

As part of a stepback review of the entire Allston project, Pollack said state transportation officials plan to utilize two other models to predict future ridership and help determine when West Station should be built. She described one, being developed by the Metropolitan Area Planning Council, as an “accessibility type model.” The other, being developed in conjunction with the T’s planning for the future of commuter rail service, was described as “dynamic modeling.”

Eric Bourassa, director of the transportation division at the Metropolitan Area Planning Council, said the CTPS model has limitations. “It’s a great tool for asking certain types of questions,” he said. “It’s not a great tool for doing scenario planning, where you’re trying to do lots of different scenarios and iterations. It’s a slower, klunkier tool for that sort of thing.”

Harvard has pledged $50 million toward the construction of West Station and $8 million toward a temporary, interim station that could be opened much sooner. Pollack, in her presentation to the stakeholders, indicated West Station as a commuter rail facility could not be started until at least 2025 because the area where the station would be built is needed as a staging area for work on the Turnpike. “It’s simply not an option,” she said of starting work any earlier than 2025.