“They had to thread the needle,” says Burke. The interchange job is due to wrap up next summer.

While the weather this year hasn't been friendly, contractors are keeping on top of their deadlines thanks in part to an available labor pool. Mainline construction work began in January. Then came the blizzard of the century, in February, followed by record rains.

“There just wasn't enough Saturdays and Sundays in this schedule, so we had to double-shift,” says Gould. Adding pressure to McHugh's tight schedule, which is based on calendar days—not business days—are four no-excuse incentives, each worth $250,000, for a total of $1 million in bonuses riding on the main line.

The flip side is another extreme, as the city is imposing liquidated damages valued at $25,000 for each day of uncompleted work for each deadline. “We're proud to say we're making the milestones,” Gould says.