Heavy-duty truck drivers are increasingly driving without a clutch pedal.

Responding to what its executives call “incredible” demand, Mack Trucks plans in March to begin offering a new 12-speed automated manual transmission (AMT), called mDrive HD, as standard equipment on its Granite construction trucks.

“We see the mDrive being a game changer in the vocational industry,” said Stephen Roy, president of Mack Trucks North American sales and marketing on Feb. 3 at this year’s World of Concrete show. “No more sore shoulders and tired legs.”

The mDrive HD is designed to be a more robust version of Mack’s existing AMT for highway tractors, with hardened gears, clutch packs and synchronizers designed to take the beating of a construction truck gearbox. By replacing the manual stick and clutch pedal with a pushbutton selector on the dashboard, Mack intends to help drivers improve their productivity and safety.

Weight is also reduced compared to competitors’ automatics. Mack estimates that the mDrive HD will be 191 pounds lighter than Eaton’s UltraShift and 237 pounds lighter than Allison’s 4500 RDS.

Introduced in 2010, mDrive now has a take rate of 50% on Mack’s Pinnacle on-highway models, Roy noted. This past October, the Greensboro, N.C.-based company made mDrive standard on those vehicles.