I Rode in the First Street-Legal Autonomous Truck

I should be anxious riding in a 30,000-pound truck at 55 mph when the driver casually turns to chat with me in the backseat and takes his hands off the wheel. But strangely, I'm at ease.

This week in Las Vegas, Daimler Trucks announced that its Freightliner Inspiration truck, an 18-wheeler with the smarts to head on down the highway without any assistance from a human driver, had been granted a license to operate on public roads. Unlike experimental vehicles from the likes of Google, the Inspiration is not limited or restricted by a special testing-only license. The trucks (there are two of them) have been granted full commercial licenses for regular operation on public roads. Daimler claims these are the first such vehicles to run on public roads anywhere in the world.

To witness firsthand just how safe and smooth the 18-wheeler is, I took a ride in one of the first demonstrations of the vehicle available to the press in Las Vegas.

Cameras, Radar and Screens Aplenty

With a low-slung aerodynamic fascia that nearly scrapes the road, and an interior cabin that looks like a high-tech man cave rather than the inside of a truck, the Inspiration is equipped with a panoply of active safety systems designed to alleviate driver fatigue.

The technology behind the system includes stereo cameras mounted on the windshield above the rearview mirror. The cameras look for lane markings to steer the truck down the road. Supporting the cameras are dual radar systems mounted in the front bumper. One long-range radar looks ahead 820 feet, while the other short-range system looks ahead 230 feet for cars that may cut in front of the 18-wheeler. 

Mark Alvick, Daimler's human driver behind the wheel, said he's logged about 400 miles in the Inspiration truck, but the company conducted more than 10,000 hours of testing to get approval for the license in Nevada. Inside the cabin, the first thing you notice are two large, high-definition vertical screens mounted on the front A pillars, with rearview camera views designed to replace the side mirrors. (The outside mirrors were also there in order to meet federal legal requirements.) 

When we were pulling out of the parking lot, Alvick explained that the side-view cameras pan with the trailer, so you never lose sight of the end of your load. Compared to old-fashioned mirrors, they also virtually eliminate any blind spots on the side.

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Autopilot Engaged

For the first part of the drive, Alvick was in command because the autonomous system has one crucial limitation: It is not designed to handle city streets. But once we were on a two-lane blacktop, Mark pushed a button to engage the Highway Pilot system, and then surrendered control of the truck to the autonomous system. Blue exterior lights mounted on the top of the cab signaled to other drivers that our vehicle was in autonomous mode.

The truck smoothly followed a chase car ahead of us, slowing down and speeding up to match the other vehicle's speed while consistently maintaining a safe 3.5-second gap. It allowed Alvick to turn around to answer questions from the backseat.

We were limited to 55 mph, per the speed limit, and the Inspiration truck was set with geo points denoting when the highway ended or our exit ramp approached so that it could warn the driver when it was time to reassume command. The Highway Pilot system will fully brake and accelerate the vehicle automatically and keep it in the center of the lane (so-called lane keeping), following curves and any undulation in the road.

What's new about this vehicle — and what separates it from everything else on the road (except experimental vehicles) — is that the driver can legally take his or her hands off the wheel for as long as the pilot system is engaged.

When the truck is in autonomous mode, the center dashboard display and instrumental panel change to show new options and apps, including YouTube, books, audio, A/C, and logistics to help the trucker plan deliveries. The center display in the Inspiration is a Samsung tablet that can also be removed from the dashboard.

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Remarkably Smooth Ride

Alvick admitted he would not feel comfortable reading a book while the vehicle drove. I asked him what the truck would do if one of the cars coming toward us suddenly veered over the center line. Rather than swerving, and potentially flipping the truck by going onto the soft shoulder, the system is designed to do an emergency braking maneuver. The Highway Pilot system can also automatically follow stop-and-go traffic, making it far less arduous to follow highway traffic congestion (although our particular vehicle was not set to do so).

Unlike some other active safety systems, I found the Inspiration's autonomous mode to be remarkably smooth. The truck includes topographic maps so that it can anticipate hills ahead, and shift and accelerate smoothly. The system also prevents jump-starts, which can not only be uncomfortable but also waste fuel and cause unnecessary wear and tear on the engine and drivetrain.

Following the road, the Highway Pilot steered fluidly, without the jerky micro corrections to stay in the lane that are sometimes seen with other systems. On Interstate 15, the truck gracefully slowed when another truck passed us and moved back in front of us. Cars that zipped in and out were also avoided without excessive braking — not a small feat for a truck that tips the scales at 30,000 pounds.

Taking Control

When we were about to approach our exit, a Take Control countdown clock started on the tablet screen. The truck cannot navigate exit ramps, either. If the driver should somehow become incapacitated due to a heart attack, for example, or refuses to respond to the takeover command, the truck will begin to brake gradually. Then, when further warnings are ignored, it will bring the vehicle to a complete stop. It will not, however, pull the 18-wheeler over to the side of the road. Once stopped, the truck could then send a distress alert to the company or place a 911 call for help.

Daimler takes great pains to emphasize that the Inspiration truck is not a driverless vehicle. A qualified driver with special training (to meet the Nevada licensing requirements) must be behind the wheel at all times. The National Highway Safety Administration calls this a Level 3 autonomous vehicle. (Level 4 doesn't require a driver at all.)

Clearly, the technology to make the Inspiration truck an everyday reality is available. Daimler AG board member Wolfgang Bernhard told Tom's Guide that the company expected to leverage the volume of similar sensors and technology already in use in cars like the Mercedes Benz S Class to keep costs down, although he declined to say how much more the autonomous features of the Inspiration would cost as an option in future 18-wheelers. 

Sooner Than You Think

As for when these behemoths of the highway would be for sale, Daimler managers and engineers repeatedly said during the demonstrations, "sooner t

han you think." All that would be needed would be nationwide regulations. But Daimler — and the state of Nevada — may have found an interesting legal way to move forward without them.

To gain roadworthy status, the truck receives a stat safety certificate. Drivers (or, in the future, car buyers) sign a document saying they understand the capabilities — and limitations — of the vehicle's technology, and the license and registration are granted. So, both the truck company and the driver are taking on extra responsibilities, beyond what most automakers or drivers do today. However, this model could be repeated, state by state, effectively by creating a de facto way for autonomous vehicles to begin appearing on the roads.

In all, there are actually two Freightliner Inspiration trucks that are now licensed to operate in autonomous mode on Nevada highways. Could they travel elsewhere, legally? There are only two states that specifically forbid it: California (which does not allow commercial autonomous vehicles) and New York (which does not allow vehicles to be operated without a driver's hand on the wheel). 

So, if you're driving anywhere else in the United States and you see a big rig with blue lights in your rearview mirror, it could be the future gaining on you.

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John R. Quain is the contributing automotive editor for Tom's Guide. Follow him @jqontech. Follow us @tomsguide, on Facebook and on Google+.

John R. Quain

John R. Quain has been reviewing and testing video and audio equipment for more than 20 years. For Tom's Guide, he has reviewed televisions, HDTV antennas, electric bikes, electric cars, as well as other outdoor equipment. He is currently a contributor to The New York Times and the CBS News television program.