FRANKFURT -- In June of last year, Germany became the first country worldwide to legalize the use of a highly autonomous driving system.

Three major stipulations were set out:

A licensed driver behind the wheel must be alert at all times; The driver must be able to manually override the system; and There must be sufficient lead time and a clear protocol before the vehicle hands back control. A data recorder is installed to document all handovers between man and machine so that liability can be determined if there is an accident.

Prior to last June, it was not permitted for anyone but the driver to operate the vehicle. If a car's sensors indicated a human was no longer in control, for example in the case of a sudden incapacitation, its onboard computer was legally prohibited from slowing the vehicle or taking evasive measures.

Fully autonomous cars such as Volkswagen's Sedric that have no steering wheel or pedals were not included since driverless cars are not allowed under the United Nation's 1968 Vienna Convention on Road Traffic, a treaty that Germany both signed and ratified. Driverless cars can, however, be tested on public roads just like any other vehicle prototype as long as the authorities have provided the usual exemption.

Some cities have approved pilot fleets operating on private property that serve as a suitable microcosm for recreating normal traffic conditions on public roads. This includes an autonomous shuttle service operated by the Berlin public transit service at the Charite university hospital grounds. Here, pedestrians, bicyclists and emergency vehicles can all be found in one enclosed area.