Sales and shipments of cutaways, low cab-over-engine and strip chassis trucks moved higher in the first two months of 2015 compared to a year ago, yet 2015 should be as volatile as 2014, according to the NTEA.

Shipments outpaced sales in January and February, logging a stronger start to 2015 than 2014, the NTEA reports in the May edition of its OEM Monthly Chassis Report. The year is "off to a good start," according to the report, which also warned of expected volatility to come.

"While some of this volatility can be attributed to normal seasonality, uncertainty has also been a factor," according to the report. "Sales trended down in the second half of 2014, and shipments dropped even more quickly."

So far this year, shipments have exceeded 11,000 units per month, while sales reached 10,000 units in January but fell below that level in February.

Chassis sales in the U.S. and Mexico have strengthened, as commercial truck chassis sales increased 13.7 percent in February compared to February of 2014, following a 12.8 percent rise in January. For the first two months of the year, cumulative sales growth reached 13.2 percent, which exceeded the 9.1 percent increase registered in 2014.

"These results indicate that growth in the work truck industry is speeding up," according to the report.

On a quarterly basis, the acceleration is even more apparent, given the 1.5 percent growth rate in the fourth quarter of 2014. Canadian commercial truck chassis sales increased 7.5 percent in February — slightly better than the 6.9 percent expansion in the fourth quarter.

Read the full report here.