A study commissioned by a CEO round table and the Boston Foundation estimates that the cumulative economic drain of reduced productivity, lost time, vehicle damage, freight delays, and other costs associated with failing to repair the state’s cramped and crumbling highways could total $26 billion by 2030.

The group endorses investment in transit as well as highways, and the cost of inaction would almost certainly be higher if the MBTA and other regional bus systems were allowed to continue to erode — forcing more transit riders onto the highways — but those costs are difficult to quantify with the same precision, the report’s lead author said.

But every dollar the state spends on transportation infrastructure yields $2.04 in immediate activity for the state economy, according to the report, through materials purchases and spending by construction workers who are employed. That’s before the longer-term benefits of that highway or transit project even kick in.

The study makes the case for investment just as Governor ­Deval Patrick is preparing a roadmap for spending as much as $13 billion more over the next decade to repair and enhance the state’s aging transportation systems, lending Patrick some influential allies from beyond the cadre of planners, environmentalists, academics, and other advocates who consistently weigh in to support transportation investment.

“This is potentially going to be a bold initiative — I hope that it is,” said John Fish , founder and chief executive of Suffolk Construction and chairman of the Massachusetts Competitive Partnership, an organization of 15 prominent chief executives. “The business community really needs to take a hard look at this and understand that if we really want to be the best state in the union, this has to be a priority.”

Lawmakers, transportation advocates, and civic and business leaders view the new legislative session as a rare opportunity to address the state’s backlog of needed repairs to deteriorating roads, bridges, and transit systems and put annual highway and transit operations on sound financial footing. But a difficult debate looms over what taxes or fees to raise, and how much.

On Monday, Transportation Secretary Richard A. Davey is expected to deliver a report ordered by the Legislature tallying the cost of all of those long-deferred repairs and replacements, as well as strategic investments in perennially postponed projects, such as restoration of commuter rail routes to Fall River and New Bedford. The report will also contain a menu of possible taxes and fees.

But the administration declined to reveal how it plans to pay for everything until Patrick delivers his State of the Commonwealth address Wednesday, followed by his state budget proposal a week later.

The Massachusetts Competitive Partnership — which includes New England Patriots owner Robert Kraft as well as the chief executives of Fidelity, Raytheon, Staples, and Partners HealthCare — and the Boston Foundation are not weighing in yet on specific taxes or a target amount. They acknowledge that new revenues will be necessary but are letting the administration take the lead.

Instead, they are setting the stage with their “Cost of Doing Nothing” report to warn that inaction or insufficient action could hamper the state’s economic recovery and erode competitiveness. The coalition promotes transportation investment to bolster the whole state, and buoy the middle class from the Berkshires to the Cape.

“This really is the moment to do something significant,” said Paul Grogan, chief executive of the century-old Boston Foundation. “It would be a shame not to seize it and end up kicking the can down the road, as governments everywhere seem to be doing.”

Fish, of Suffolk Construction, called transportation “one of the most important ingredients” for the success of any business, and for the state.

“Time is a commodity we can’t buy any more of,” he said. “We’ve gone on too long without really repairing what we currently have now and putting in a solid strategic plan for the future of how we improve the quality of our transportation systems.”