The testing facility, Ford's largest, is where vehicles undergo strenuous durability tests before being deemed fit for production. Intimations of pulpy 1950s sci-fi cinema aside, the robots’ presence should not provoke alarm, as they are monitored 24 hours a day as part of Ford's new durability testing regime.

Roughly three years ago, Ford personnel sat down to discuss how to make truck durability testing safer for its drivers. By October 2012, Ford was testing the F-Series Super Duty pickup truck using robots. "We think it's the world's first robotically driven durability vehicle," Dave Payne, Ford's manager of vehicle development operations, said.

Ford employs United Automobile Workers (UAW) members at its Romeo proving grounds. Unlike some automation projects at UAW-organised assembly plants, Payne said the test drivers supported the move toward robotic testing from the proposal’s beginning. "They knew from the start that we'd be working on this, and they actually helped us select which roads to implement this on because there's obviously certain roads they really don't like to drive."

One of those routes involved driving a large truck just under the size of an 18-wheeler over a 2ft-deep ditch measuring 12ft across – and there were two of them in a row. "You have to drive that truck over that [ditch] at 2.5mph and do it 27,000 times," Payne said. "The first couple drivers came to us and said, 'I can't do this test.' They were getting beat up inside the truck. So we put the robot in it."

The robotic driving system was designed by Autonomous Solutions, a Utah-based company that creates autonomous vehicle systems primarily for mining, agricultural and military clients. The system consists of an on-board computer within the truck, which sends signals to actuators that pull and push cables for the shifter, accelerator and brake pedals. The equipment costs come under $100,000 per vehicle.

Scattered around the proving grounds are radio and wi-fi antennas that work with GPS units to pinpoint each truck within an inch of its location. Each truck essentially has spatial awareness. "It's got a map of the site, and it knows at this section I want to go 10mph, when I get to the next section I might speed up or slow down," he said. "Once we're up and running it can pretty much run on its own."

All vehicles communicate with a manned base station where up to eight robotic vehicles can be monitored at once. Each vehicle’s movements are strictly choreographed, to the point that one truck can safely cross in front of another. But if bumpers get too close, the base station sends a signal telling the trailing vehicle to slow down.

Payne claimed the robot model saved Ford about two to three weeks on durability testing, relative to the old model, but time savings was a secondary benefit."The bigger picture, I think, is taking drivers out of harm’s way and putting them on other testing that's more technical," he said.

As Ford has learned the robots’ capabilities and how accurate the data can be from the tests, it has increased the use of robots for other test applications. Not only do the robots handle the strain better than humans, but they also provide more precise data because they are impervious to fatigue. "The robot doesn't have a bad day," Payne said.