It may seem odd to characterize North America’s projected production increase of nearly 40% this year as “cautious,” but the term fits.

Auto makers are on track to build roughly 12 million light vehicles this year, compared with 2009’s decades-low 8.56 million, while utilizing only 65% of their capacity in the U.S., Canada and Mexico, Ward’s data indicates.

Last year’s 49% utilization rate largely was a reaction to bloated inventories and extended bankruptcy-related shutdowns at General Motors Co. and Chrysler Group LLC.

In contrast, 2010’s low utilization rate is a result of strategic discipline, as auto makers allow demand to dictate their build rate, rather than use production to push the market upward.

Combined LV sales in the U.S., Canada and Mexico are forecast to rise 9% in 2010, finishing at a projected 13.7 million units. As a result of the new build strategy, inventories, which began the year below 2 million units, remained at or just below 2.2 million units through the first three quarters as sales and production increased slowly but steadily.

However, with the ramping up of the ’11 model year, inventories have been on the rise, especially in the fourth quarter. U.S. stocks, alone, are expected to surge to 500,000 units by the end of December, with domestic-built vehicles accounting for more than 90% of the increase.

Ward’s is forecasting a continuation of cautious LV production growth in North America, rising 12% to 13.4 million units in 2011, against a 16% increase in sales for the region, resulting in 15.8 million cars and light-truck deliveries.

At projected levels, OEMs collectively are expected to operate at 73% of capacity.

Several plants are set to end production in 2011, which should ease the under-utilization rate somewhat. Ford Motor Co.’s Wayne, MI, facility is slated to shut its doors at the end of 2010. Louisville also will end its operation this year, although that plant’s fate has yet to be announced.

Additionally, Ford’s St. Thomas, ON, Canada, and Twin Cities, MN, facilities are schedule to stop manufacturing next summer with the completion of the ’11 model builds.

Toyota Motor Corp.’s plant in Fremont, CA, built cars through April before closing. It since has been sold to Tesla Motor Co., which plans to build its own electric vehicles, as well as some Toyota models, beginning next year, albeit at much lower volume.

However, the majority of North America’s lost capacity associated with the shutdowns will be offset by production at new or reconfigured plants in 2011.

Ford begins making its ’11 Focus compact car late this year at its retooled Michigan Assembly plant, the former Michigan Truck facility in Wayne, MI, and could build as many as a quarter-million vehicles at the plant in 2011.

GM is set to restart its Orion, MI, plant, to produce the Chevy Aveo in second-half 2011, just as Volkswagen of America Inc. revs up its new Chattanooga, TN, operation. Both facilities could build as many as 100,000 vehicles in the year’s second half.

Toyota says it will begin Corolla production at its new Blue Springs, MS, facility in fourth-quarter 2011, adding some 30,000 units to the industry’s total 2011 build.

In addition to the plant openings, Kia Motors America is expected to nearly double its North America output next year to about 240,000 vehicles annually with the addition of the Hyundai Santa Fe alongside the Kia Sorento in West Point, GA.

GM’s Lordstown, OH, factory will mark its first full year in 2011 building the all-new Chevrolet Cruze, lifting annual output by at least 100,000 units to an estimated total of 250,000.

GM’s Hamtramck, MI, facility’s output should increase markedly with the recent addition of the Chevy Volt extended-range electric car, and the high-volume Chevy Malibu starting in second-half 2011.

Ward’s expects Volkswagen de Mexico S.A. de C.V’s Puebla, Mexico, plant to be the largest producer of LVs in 2010, displacing Toyota’s Georgetown, KY, factory, which built 420,000 units in 2009, compared with Puebla’s 402,000. VW should increase its lead as it continues ramping up production of the new ’11 Jetta next year.

GM, which narrowly edged out Ford as the region’s top LV producer in 2009, (Ford actually built more vehicles if medium- and heavy-duty trucks are included), will be the solid No.1 producer for 2010, with projected output of 2.8 million units to Ford’s 2.3 million.

Chrysler, which slipped to No.4 in 2009, behind Honda of America Mfg. Inc., will regain the No.3 spot in LV production this year, with 1.6 million units, followed by Toyota Motor Engineering & Mfg North America Inc., with 1.29 million, and Honda, with 1.28 million.

Ward’s forecast calls for the auto makers to finish in the same order in 2011.

By region, Ontario, Canada, will be the top LV-producing state or province in North America this year, rolling out an estimated 2.1 million vehicles, followed by Michigan, with 1.6 million and Ohio, with 1.1 million.

Medium- and heavy-duty truck producers are predicted to make 230,000 vehicles this year, up 15%, bringing the total North American vehicle build in 2010 to 12.2 million units, up 39% on year-ago.

Ward’s is forecasting 2011 medium- and heavy-duty production of 300,000 units, up 29%, for a North American total vehicle gain of about 12%.