Hands off the wheel.

  • 28. May 2015
  • Autonomous Driving
  • Photos: Daimler
  • Text: Patrick Solberg

Daimler’s US subsidiary Freightliner is testing autonomously driving trucks on public roads so that trucks will be able to travel the highways by themselves from 2025.

The US truck market is hotly contested. Logistics companies such as Swift Transportation, Schneider and J.B. calculate their every move, and examine every fact. If necessary by making their own measurements. The No. 1 maxim is cost-effectiveness and efficiency. “Our customers are our inspiration” is the adage that Martin Daum impresses on all his staff. The embodiment of this adage is standing just a few metres away from him, and carries the name “Freightliner Inspiration Truck”. Within ten years this truck weighing over 30 tonnes is set to revolutionise goods transport by driving autonomously from place to place.

Like learning to ride a bicycle

Daimler already took the first step towards autonomously driving trucks one year ago, when the Mercedes-Benz Future Truck 2025 passed a test with flying colours on a closed-off section of motorway in Germany. Neither did the system encounter any problems in a subsequent endurance test covering 16,000 kilometres on a closed-off route. The US state of Nevada has now given the green light for test operations on public highways.



Slim headlamps with blue LED light bands which are repeated in the sides of the front apron and the radiator grille distinguish the Inspiration Truck from the Freightliner Cascadia on which the prototype is based. Two of these eye-catching test vehicles are now to start driving autonomously on the roads of North America to help improve the technology to production maturity. To this end the two trucks are crammed with modern technology. “We use near-series sensor systems,” says Sven Ennerst, Head of Global Development at Daimler Trucks.


Known as the “Highway Pilot”, the technology consists of two radar sensors located in the vehicle’s front apron. There are also a stereo camera and a number of assistance systems such as Adaptive Cruise Control, Active Brake Assist and Active Lane Keeping Assist.


The two radar sensors have different purposes: the long-range sensor is responsible for predictive driving, scanning the road to a distance of 250 metres with an arc of 18 degrees. The second radar sensor sends out its signals with an arc of 130 degrees, but has a range of only 70 metres. Thanks to the wide field of vision, other vehicles cutting in can be recognised at an early stage and the driving style adapted accordingly. The same applies to the long-range sensor, which registers traffic travelling ahead and reduces the speed if necessary, while the camera with a range of 100 metres follows the road markings to keep the Inspiration Truck on course. All of these components have already absolved many thousands of kilometres in production vehicles.



The interaction between these individual systems is controlled by highly sophisticated software which enables the Highway Pilot to take over control of the vehicle. The procedure is similar to that used in autonomously driving Mercedes-Benz passenger cars. “We work together closely with our colleagues,” says Sven Ennerst. The development of autonomously driving trucks is however aimed specifically at operations on major highways and motorways. In town and on motorway access roads the driver must still control the truck. But as soon as the approx. 26-metre long combination reaches US Highway 15 near Las Vegas, the system announces its operational readiness with a display in the digital instrument cluster.

Mark Alvick presses a button to activate the auto-pilot and relaxes with his hands in his lap. When asked what it felt like when he activated the system for the very first time, the test driver answers: “Just like when I was learning to ride a bicycle, and my father stopped holding me for the first time.” The technical assistants control the heavy combination as confidently as a veteran trucker who has absolved many thousands of kilometres on the highways.


The 505 hp Inspiration Truck takes every bend smoothly, without any hectic or abrupt steering movements. The system also responds calmly to the other drivers who overtake the prototype truck on the left and right and cut in ahead of it. If the distance to another vehicle becomes insufficient, the Highway Pilot gently applies the brakes while staying on track. The technology is not capable of overtaking manoeuvres, as the object of autonomous truck driving is to glide along smoothly. This reduces fuel consumption by around five percent, and increases safety.

Pleasant journey in leather, wood and aluminium

As soon as the Highway Pilot becomes unable to perform as required owing to poor visibility or the absence of road markings, it prompts the driver to retake control with a message in the instrument cluster and then initiates a countdown. If the trucker fails to respond, the last five seconds are counted down to the accompaniment of clearly audible beeps. If there is still no driver response, the system gradually reduces the truck’s speed and finally brings it to a halt.


Yet even then the Highway Pilot is adaptable: as soon as the conditions permit, it automatically takes the wheel again and continues the journey. Mark Alvick illustrates his view of the future of autonomous driving with another metaphor from his childhood: “Have you ever heard of a person reattaching the support wheels to his bike after learning to ride it?”



The individual technologies will be gradually introduced until the Highway Pilot enters series production. In the next few years Tailback Assist will reduce the workload of truckers. The driver remains the deciding factor. While the technology controls the truck, the driver can perform other tasks of if desired deactivate the Highway Pilot and retake control. “Studies have shown that drivers in autonomous trucks become tired less quickly,” says Sven Ennerst.


Companies too benefit from wide-awake drivers who can put their time behind the wheel to better use. Autonomous driving will change the future of the logistics sector. Because trucks are and will remain the most important means of transport in the USA. Around 70 percent of all goods are transported by road. Indeed the volume of road goods transport is forecast to triple by 2050.



As the vehicles will be in operation more or less around the clock, the cab of the Inspiration Truck has a designer interior akin to an elegant lounge: the seats are lined in fine white leather, as are sections of the instrument panel and the comfortable sofa in the rear living area of the cab. As on an upmarket yacht, the flooring is of wood planks rather than carpeting. Like the surrounds of the camera monitors on the A-pillars, the door handles are of aluminium. A removable tablet is the central control unit in the truck’s cockpit.

There are additional cameras in the exterior mirrors and vehicle body which give the driver an all-round view. The image is transferred to the monitors positioned on the A-pillars. Thanks to the cameras the exterior mirrors are smaller than in current trucks, which lowers fuel consumption by one percent. The Inspiration Truck has also captured the enthusiasm of Dr. Wolfgang Bernhard, the Board of Management member for Daimler Trucks: “I am very proud of this extraordinary achievement by the team at Daimler Trucks.” The first autonomously driving prototypes will soon also be tested on public roads in Germany. “The relevant preparations for this are now being made,” says Wolfgang Bernhard. The future of the autonomously driving truck is already assured. As soon as the system works perfectly it is to be introduced into other countries outside the USA.

A rear just as spacious as a conference room.

Related topics.