At General Motors, nearly one in five U.S. hourly workers now clocks in close to midnight and goes home around sunrise.
GM has more assembly plants in North America running overnight than the entire auto industry did at any point from 2000 through 2009.
"They're going to three shifts at just about every plant now," says George Ruiz, president of UAW Local 31 in Kansas City, Kan. GM's 25-year-old plant there, which never ran on more than two shifts until January 2010, has had three ever since.
GM -- prodded by the Obama administration's auto task force, which viewed overnight downtime as a lost opportunity for profits -- was the first automaker to begin using three shifts widely as the industry recovered from the recession.
Ford Motor Co., Chrysler Group, Nissan Motor Co. and Kia Motors Corp. have followed suit, and many of their suppliers have added overnight shifts in turn. Hyundai Motor Co. begins a third shift at its Alabama plant in September.
By the start of next year, 22 of the 83 assembly plants in North America will operate with three shifts of workers, and nearly half of all vehicles built here will come from a three-shift plant, according to forecasts by IHS Automotive. "It's never been that high," says IHS analyst Michael Robinet.
"The days of building vehicles on two shifts and being satisfied with that are finished," Robinet says. "They are absolutely going to maximize their brick-and-mortar as much as possible."
Even when sales surpassed 17 million vehicles a year in the early 2000s, no more than seven out of more than 100 assembly plants ran on three shifts at any one time, according to IHS. But with fewer plants open now and industry sales on the rise, a traditional, two-shift schedule is not sufficient for many hot-selling models, such as the Chevrolet Cruze, Ford Focus and Nissan Altima.
And as the market continues to rebound, Robinet and other analysts say three shifts will not be enough either. Automakers soon will need to bite the bullet and build plants to avoid losing sales to rivals.
"These sorts of shift arrangements only work for so long," says Sean McAlinden, chief economist at the Center for Automotive Research. "Some big decisions have to be made. We've got to put some buckaroonies down and build capacity to grow with the market."