Early 2019 has never looked so near. Or so attainable.

As Seattle Tunnel Partners continues to build on its success in 2016, the Washington State Dept. of Transportation-owned effort to replace the aging Alaskan Way Viaduct with a nearly 2-mile-long tunnel under downtown Seattle is now one-third complete, a sight many weren’t sure would ever come after a roughly two-year stoppage on tunneling.

Since tunneling resumed on the project in late December 2015, crews have mined 2,100 feet and the future highway is getting built inside the completed portion of the tunnel. Progress is now visible at the north and south portals where tunnel operations buildings and future highway connections near completion.

For the Alaskan Way Viaduct Replacement Program, 21 of the total 31 projects are now done—the program is now a decade old—and half of the viaduct has been demolished and replaced.

At the north portal for Bertha, the world’s largest diameter tunnel-boring machine, Atkinson Construction is building the highway connections for the tunnel near the Space Needle, and crews from Interwest Construction are preparing to start work on a newly awarded contract to build a bridge near the stadium district to serve as an exit from State Route 99 at the south portal once the tunnel opens.

While work is now moving forward, that doesn’t mean it hasn’t come without major hurdles, not even counting the years lost in delay. Along with the overall construction costs, there are additional costs for contract administration and project oversight. The costs to acquire right of way along the tunnel alignment also rose higher than projected and demolition costs will come in higher than budgeted due to the tunneling delay. All the extras—not counting actual repair costs—in the $3.1 billion project will require an additional $223 million, a potential 6.6 percent increase from the plan, with about $60 million related to the delay.

“We will continue to follow the terms of the design-build contract to recover the added costs that are due to the delay of the project,” says Roger Millar, acting transportation secretary. This will include pursuing insurance claims, identifying potential cost savings in other elements of the program and ongoing litigation to recover damages. Even if successful, the additional funds will likely not come available until the completion of the project.

As program officials crunch the financial numbers, Bertha was undergoing a refresh of its own crunching tools. During a planned maintenance period that included more than 40 shifts of work under hyperbaric conditions, Seattle Tunnel Partners changed 33 of more than 700 cutting tools.

Bertha will next tunnel north toward First Avenue and Seattle Tunnel Partners expects two more maintenance stops before reaching the north portal near the Space Needle.

Follow Tim Newcomb on Twitter at @tdnewcomb.