The estimated cost of the underlying project — replacing the decrepit Route 95 North bridges and interchange in the center of the city while adding new travel lanes — has grown from $226.1 million to $342.9 million.

The price tag to repair and expand Route 95 through downtown Providence has ballooned as Rhode Island looks to take advantage of President Donald Trump's preference for public-private infrastructure partnerships.

The state last month applied for a $60-million grant from the U.S. Department of Transportation's "INFRA" program for the reconstruction of the Route 95 Northbound Providence Viaduct, roughly the same project it sought a $59-million grant for a year ago under the Obama administration's predecessor "FASTLANE" program.

But the estimated cost of the underlying project — replacing the decrepit Route 95 North bridges and interchange in the center of the city while adding new travel lanes — has grown from $226.1 million to $342.9 million, according to the respective grant applications from the Rhode Island Department of Transportation.

A big chunk of that cost increase is connected to financing and the private part of the project. This year's grant application says the "estimated design-build cost" is $264 million. The new plan then adds interest on a $45-million private loan and a "15-percent return to the private partner."

Built in the 1960s, the northbound viaduct carries Route 95 over the Woonasquatucket River, Northeast Corridor rail line and multiple local streets. It's in bad shape.

The DOT says the bridges are in "poor structural condition," carrying more vehicles than they were designed to handle and one section is "fracture critical, necessitating frequent and costly patchwork repairs just to keep it and the surrounding stretch of I-95 functional."

After four years of work, the state completed reconstruction of the southbound Viaduct in July at a cost of $105 million, 16 months behind schedule, according to DOT's latest quarterly report.

Replacing the northbound Viaduct and ramps in their current configuration is projected to cost between $120 million and $170 million, the grant application says.

But DOT leaders consider this part of Route 95 North not only dilapidated, but one of the worst traffic choke points in New England, and they want to redesign the highway with separated local and express lanes to avoid the congestion-causing vehicle weave that happens now.

"We stand on the cusp of a once-in-a-lifetime decision: to alleviate the current ills of [sic] third-most traveled segment of interstate in all of New England, or simply replace the Viaduct in-kind, which would lock in longstanding safety and congestion challenges that currently plague this stretch of I-95 for the next 70 years," DOT Director Peter Alviti Jr. wrote in the grant application.

As in last year's proposal, the new DOT plan would separate local traffic heading for the Route 146 and Orms Street exits from vehicles heading toward Pawtucket and Boston, adding two extra lanes to the narrowest section of the highway.

It also retains an idea devised by Providence planners to tear up the circular Dean Street-Route 6 on-ramp to reclaim 5 acres for potential development and the expansion of the popular DePasquale Square commercial area on Federal Hill.

Gone from last year's Viaduct plan is a $15-million pedestrian bridge over Route 95 between the Providence Place Mall and Promenade Street, which Alviti said last week was removed to save money.

Even with the pedestrian bridge taken out, the estimated cost of the viaduct project jumped 59 percent from a year ago when the new financing plan is taken into account.

"The $226-million figure from the original FASTLANE grant application was a rough estimate for the cost of the project. It is important to remember that this project is still in the very early concept and scoping phase," wrote DOT spokeswoman Lisbeth Pettengill on the reason for the spiraling costs.

Why would the state seek a private partner and use private loans when its own borrowing costs are lower and it is about to see a new stream of bridge repair money from truck tolls?

"When the [Trump] administration came in, they stopped the FASTLANE process and redefined the grant guidelines. The new guidelines encourage states to find private partners and to take more of a role in funding projects," Pettengill wrote. "With these guidelines in mind, we redefined the project to fit those new grant requirements."

Trump has said he will unveil a federal infrastructure plan early in the new year. Based on his campaign proposals, the plan is expected to have a heavy emphasis on public-private partnerships.

Beyond financing, Pettengill said private partners can bring additional assets as well as extra costs.

"This delivery method created additional costs, particularly due to the costs associated with private sector equity funding the project," she wrote. "We are seeking the new grant to offset those costs."

If the state doesn't get a federal grant, Pettengill said the DOT will reevaluate "all options" for the project and its financing, keeping in mind that the viaduct must be replaced at some point.

— panderson@providencejournal.com

(401) 277-7384

On Twitter: @PatrickAnderso_