Its creators, scientists from the University of Berkeley and members of the National Automated Highway System Consortium, were proud to call it "really dull". Once the computer takes over, the driver does not have to operate the pedals or even steer.
"It's really exciting for about the first 15 seconds, then it gets really dull," said Jim Rillings of the NAHSC.
"It's like driving with a chauffeur. You just sit back and let your mind wander."
The test was purely a demonstration; the specially-equipped cars, which have radar and desktop PCs on board, are not available to the public.
But the NAHSC intends to have its system, on which it has spent $20m, up and running by 2002.
The automated highway is a reaction to increasing gridlock on America's car-filled, bus-empty and train-bereft transport system.
The traffic begins building up at 5am outside Washington DC, while some commuters near California's main work centres have to leave home at 4am to get to work on time. The system works by detecting magnets buried about 1.2 metres apart on either side of the road, providing the directional information allowing the car to follow the road. A built-in radar also takes note of the distance to the car in front.
The dozen cars and buses in the demonstration project are equipped with tiny video cameras facing forward that also follow visual aids along the road. These could be cement barriers or even deep tracks in a snowy road.
Supporters of the project insist it will save millions of federal dollars, as it relies on the existing infrastructure and would eliminate the need to build more freeway lanes. Vehicles could travel faster and closer, reducing fuel use (through slipstreaming) and, the inventors hope, accidents.
It would cost less than $10,000 to equip one mile of freeway with the new technology, compared with anywhere from $1m to $100m to build each mile of new highway, said Dick Bishop, a transportation department spokesman.
However, it looks like the automated highway will not come without roadworks. As ever, the delays will get worse before they get better. Jim Baxter, president of the National Motorists' Association, has dubbed the new system "undriving", and warned: "We may be living in the golden age of commuting, and not even know it."