DETROIT — Toyota acknowledged Thursday that, like its rival automakers in Detroit, it misjudged the drastic swing in the American market away from larger vehicles.

With sales of pickups and big S.U.V.’s tumbling, Toyota said it would shut down truck production at two United States plants for three months and consolidate its pickups into one factory next year.

The Japanese automaker also said it would begin making its Prius gas-electric hybrids in a new plant in Mississippi by late 2010 to meet demand for more fuel-efficient vehicles.

“It shows that Toyota is just as fallible as anybody else,” said Joseph Phillippi, a principal of AutoTrends Consulting. “They’re human after all.”