For many reasons, Daimler has a right to be excited. By partly automating its trucking system, the company could offer trucks that are more fuel efficient, cutting down on emissions (up to 5 percent, Daimler claims). It works, but the many obstacles loom large.

They were saving the official reveal for that evening, when we were brought to the Hoover Dam. There, the company had organized an event befitting the locale: there was a 45-minute presentation projected onto nearly the entire 726-foot height of the dam that included a brief history lesson of Freightliner, another of the dam’s construction, and a live discussion with Daimler’s executives hosted by Rutledge Wood, host of the US version of Top Gear . After all of that, the Inspiration truck finally wound its way down the roads on the Arizona side until it made its way across the Hoover Dam. (It was unclear whether the truck drove itself onto the dam.)

The Inspiration was teased to the press at this location early in the afternoon, but it was quickly driven off the premises by Nevada Governor Brian Sandoval and Dr. Wolfgang Bernhard, the head of Daimler Trucks North America, almost as soon as the giant car cover was removed. (It was unclear whether they let the truck drive itself once they got on the road.)

Daimler, which has over 40 percent of the US trucking market, brought nearly 200 members of the press to a parking lot adjacent to the Las Vegas Motor Speedway. We passed through a giant arch that read "Freightliner Proving Ground," and found an oasis of giant white tents.

The truck that Daimler debuted last week is one of only two that are licensed to drive on public roads in Nevada, and only four other states allow testing of autonomous vehicles right now. (Arizona isn’t one of them, which makes the decision to debut the truck by driving over a landmark that spans two states a bit laughable.) That’s a big issue; you can’t perform any interstate commerce if you can’t go between states. But it’s also a problem because Nevada has a particularly stable climate, which means that the 10,000 miles of testing on the Inspiration Truck have been pretty homogenous, something Bernhard freely admits. "We still have to see how this thing performs in the rain, the sun, cold days, subzero [temperatures], and very hot," he says.

Right now, autonomous trucks are stuck in Nevada

Perhaps as problematic as the regulatory issues Daimler faces is that the Highway Pilot system — for now, at least — relies on well-painted safety lines on the roads that the trucks drive down. If the lines aren’t clearly visible to the truck’s cameras, the system just won’t work. That may sound like a negligible issue, but we’re notoriously bad at maintaining our infrastructure as a country.

The next day we returned to the Proving Ground to find six trucks — two Inspirations, two of the company’s aerodynamic SuperTrucks, and two of its Cascadia trucks, which the Inspiration is based on. I hopped into the Inspiration and found a spartan, futuristic cab — there was a dynamic, full-color LCD display in front of the driver and a Samsung Galaxy Tab 4 to his right embedded in the smooth dashboard that curved down to the hardwood floors.

The Freightliner driver took us out of the speedway grounds and onto Nevada State Route 604. Less than a mile down the highway, the truck alerted him that the Highway Pilot system was available. He tapped a button, took his hands and feet off the wheel and pedals, and our 20-ton vehicle was driving itself.

We meandered down the right lane of SR604 until it met up with Interstate 15, which we took back to the speedway. All the on- and off-ramps were handled manually, which meant only a portion of the drive was autonomous. For the most part, the ride was unremarkable, which is essentially the whole point. There was just one slight curve in SR604 that afforded the only uneasy moment; while there was no doubt in my mind the truck would make it through, my gut definitely felt otherwise.

The ride was somewhat unremarkable, which is the whole point

In between thumb twiddling and glances out the driver’s side window, my driver-turned-passenger explained that the cameras in the windshield and the radar in the front bumper will assess road conditions in real time and tell the driver whether the Highway Pilot system is available. For the purposes of the day’s demonstrations, however, there were GPS-designated zones on each highway that made the autopilot system operable. The driver is in control of the speed — Inspiration doesn’t have the ability to read speed limit signs — and if the Highway Pilot deems the road unsuitable or notices an obstacle ahead, it will begin visual and audible countdowns and alarms. To regain control, the driver simply returns his hands to the wheel.

Representatives spent both days talking ad nauseam about how Highway Pilot won’t completely obsolesce the role of the truck driver, which is clearly a critical component to gaining acceptance from truck drivers and their supporters. Daimler president and CEO Martin Daum said it will "enhance" the driver’s capabilities, and Bernhard says it makes the job "much more attractive." They envision a world where the driver has more time to manage the logistics of the trip, but it’s easy to see why people might be concerned about other distractions.

Bernhard said there’s no plan to install sensors or cameras to ensure a driver doesn’t nap or play Angry Birds during the drive, but Daimler might not have to — for now, even with the autopilot engaged, accident liability remains with the driver. That’s as good of a motivation to keep a driver in his seat as any.