Daimler tested the self-driving truck in Germany in July, but on a stretch of motorway with no other traffic on it.

German carmaker Daimler has unveiled the world's first self-driving truck authorised for use on public roads at a launch on the iconic Hoover Dam in Nevada, United States.

The Stuttgart-based company said in a statement Nevada had approved two Mercedes-Benz self-driving trucks called Freightliner Inspiration for regular driving on public roads.

Head of Daimler's truck and bus division Wolfgang Bernhard said the company was currently seeking authorisation in Germany.

Daimler tested the truck in Germany in July, but on a stretch of motorway with no other traffic on it.

The vehicles have smart systems, including sensors and active speed regulators, and are authorised for use without a human driver - although, one has to be present to monitor the system and take the wheel if necessary.

Mr Bernhard said the authorisation to drive on roads in the US was "an important step for self-driving trucks".

Mr Bernhard told German media that besides increased safety compared to human drivers the trucks could save up to five per cent fuel.

He said the truck would make the driver's job "less tedious and therefore more attractive" but would not be available before 2025.

"Self-driving cars in urban settings, where traffic conditions are more complex, are even further off," he said.

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Mr Bernhard said the truck was launched on the iconic Hoover Dam for a reason.

"The Hoover Dam provides the ideal setting for a debut as significant to the trucking industry as this," he said.

"Not only was it built primarily using trucks, but it signifies inspiration like few other structures in the world.

"To show the significance and opportunities of autonomous driving functions for the global trucking industry we were willing to go ways that people did not dare to think about before," he added.

Daimler, whose vehicles include the high-end Mercedes-Benz range and compact Smart cars, is also the world's biggest maker of trucks.

AFP