If there was any question that the used-truck market came back to life in 2010, data released this month by the ATD/NADA Official Commercial Truck Guide should squash all doubts.

Values in almost all segments are up year-to-date, but the real story lies in the YTD increases within certain model years, says Chris Visser, editor of the guide. Trucks new to the secondary market (4-5 years old) saw the biggest increases, with traditional and extended hood trucks - the segment previously assumed to be dead - seeing the biggest bump.

One major reason for this shift in market dynamics is demand for low-mileage equipment, Visser says. "Selling price is closely correlated to mileage," Visser says. "Even before the Great Recession, mileage was becoming the primary factor in the value of a used truck. This trend is even more evident now that fewer low-mileage trucks are available in the marketplace thanks to the low production rates of the past three years."

Sales are also looking up. On the retail side, the total number of sales reported by dealers increased 22 percent from January to August. On the wholesale side, August sales were about 5 percent higher than January's.