A driverless shuttle bus had been on the road in Las Vegas for no more than two hours after its unveiling on Wednesday before it collided with a truck.

However, the only glitch appeared to be in the truck driver's attention, as city officials blamed the human for the accident rather than the computer-driven bus. The truck driver was issued with a traffic citation for illegally reversing.

Read more: Speedbumps on way to driverless world

"The shuttle did what it was supposed to do, in that its sensors registered the truck and the shuttle stopped to avoid the accident," Las Vegas police said in a statement. "Unfortunately the delivery truck did not stop and grazed the front fender of the shuttle. Had the truck had the same sensing equipment that the shuttle has the accident would have been avoided."

The autonomous Arma shuttle, manufactured by the French firm Navya, was subsequently taken out of service later Wednesday, having gone through a year-long trial program in Las Vegas to test its autonomous services. It is expected to hit the road again soon.

Among the shuttle's celebrity passengers who got to try the bus before the crash were NASCAR driver Danica Patrick and magic duo Penn and Teller.

Free driverless transportation

The oval-shaped driverless shuttle, which can transport up to 12 people at a time, is part of a collaborative pilot project between Navya and the Keolis transport group, which will provide free public transport in downtown Las Vegas, away from the lit up casino-lined Strip.

Sponsored by the American Automobile Association, the program has been billed as the first US public self-driving shuttle service.

"In addition to studying how the shuttle interacts in a live traffic environment in downtown Las Vegas, AAA will survey riders on their experience in order to understand why a large percentage of consumers remain wary of driverless technology and whether a personal experience changes their perception," city officials said.

Read more: Singapore public to test self-driving taxis

The shuttle uses GPS, electronic curb sensors and other technologies to inch down the city's streets, going no faster than 15 miles per hour (24 kph). AAA said it expects some 250,000 to ride the shuttle during the one-year pilot period.

The Arma shuttle unveiling comes just a day after Google's self-driving car project, Waymo, announced that it was launching its first fleet of driverless taxis in Phoenix, Arizona. Ride-hailing company Uber also launched its driverless vehicles in Arizona this year, although in one incident, an Uber car rolled onto its side after the driver of another vehicle failed to give way.

dm/sms (AP, AFP)