Two companies that track commercial vehicle sales say truck orders were down in February, but they're still continuing at a relatively healthy level.

ACT Research reports that preliminary net orders in North America were down from January, with close to 22,500 units for Class 8 trucks and 12,800 for medium-duty Classes 5-7 vehicles. FTR Associates' numbers show Class 8 truck net orders of 22,243, which was 11% below January. This was the second month in a row of negative month-over-month and year-over-year comparisons.

FTR notes that February orders annualize to 266,900, which is within the average order rate for the past nine months.

Both companies say the drop in numbers is not something to worry about, but don't expect the same type of growth in 2012 we saw in 2011.

"February net orders were incrementally below expectations," says Kenny Vieth, president and senior analyst at ACT. "However, healthy backlogs and strong orders over the previous four months continue to support our forecasts for 2012."

Jonathan Starks, FTR's Director of Transportation Analysis, said demand for new trucks "remains robust as fleets continue to replace aging equipment."

Starks notes that with the driver supply moderately tight and freight demand healthy, but not surging, fleets are likely to only add limited capacity to their truck fleet.

"Absent additional freight growth or regulatory hurdles, the new truck market in 2012 is unlikely to see the type of growth that we had in 2011."