Autonomous trucks are coming.

Ten years after Terramax - the world’s first fully-autonomous truck - competed in the DARPA autonomous vehicle Grand Challenge, Mercedes-Benz’s Daimler Truck unit has run the first public road test of its new production model robo-truck.

They ran a modified Actros semi on the Autobahn, using the truck’s radar-assisted Highway Pilot system to control the vehicle during an open road stretch of the trip.

It is not the first open-road test of an autonomous truck, but it is the first time a vehicle based on a production model has been used in public.

The Highway Pilot system uses a short-range radar to scan up to 70 metres ahead in a forward-facing arc, while a longer-range unit scans 250 metres ahead in a much smaller arc. It also features stereo cameras for detecting signs and lane markings.

The system is designed only for use on a highway, so it does not need all the additional sensors that a fully autonomous vehicle like Google’s self-driving car does.

The autonomous system is activated by the press of a single blue button, but it will alert the driver and hand back control if it detects a driving condition it cannot handle, such a traffic jam or job site.

Mercedes’ Highway Pilot system is considered a Level 3 autonomous vehicle system — meaning it can only control the vehicle in certain situations.

Mercedes says circumstances like construction sites, exits, and surface streets are outside the Highway Pilot’s purview, just like lesser automated systems found in high-end passenger cars.

The next step up is Level 4 autonomous vehicles, and it is a massive difference between 3 and 4.

Level 4’s are designed to drive themselves anywhere and everywhere without the need for human intervention.

There is a social gap too, as Level 3 vehicles still require a human component like a taxi driver or truck driver.

But Level 4 vehicles, like Google’s prototype self-driving car, do not need a human at all.

It means Level 4 vehicles will be used for everything from war zone transport to cheaper freight and taxi services.

Mercedes has been careful to keep its new truck within Level 3 parameters, so as not to replace human drivers.

The company says its new trucks will make drivers free, not redundant.

It says drivers will be able to relax while their trucks speed along monotonous highway stretches. The showcase video for the autonomous control system describes it as “Independence Day” for truckers.

The video shows a driver stretching out and using a tablet while the truck drives itself.

It is unclear whether internal systems will monitor for sleeping drivers.