CHINO, Calif. — The turning radius took some getting used to. So did the gigantic steering wheel. But the electric version of the Freightliner Cascadia big rig was otherwise easy to drive, as I navigated the warehouse parking lot, dodging delivery trucks for Amazon and J.B. Hunt.

Being 80 feet long, it didn’t quite offer the golf cart experience I was promised when its regular driver, Karl Williams, let me take over the controls, though the acceleration was effortless. There was no stick shift to wrestle, no deafening diesel engine. Just a pair of buttons to turn it on and release the air brake, and I was off.

“Anybody can drive one,” Mr. Williams said, moments before a middle-aged mom proved his point.

Mr. Williams has been a truck driver for 22 years, logging at least a million miles with diesel power. Since December, he has been testing the battery-electric eCascadia as part of a pilot program in Southern California.

“It’s beautiful,” he said. “You don’t go home with your ears ringing every night.”

Two years ago, the eCascadia was nothing more than a PowerPoint presentation — a virtual rendering to expedite a diesel stalwart into a zero-emissions future for goods movement. Now it’s one of several competing models, from start-ups as well as established truck makers, that are gearing up for production next year with real-world testing. Orders have poured in, from companies eager to shave operating costs and curb emissions, for trucks that won’t see roads for months or even years.