The news carried by Reuters on Thursday, June 25, that two self-driving cars from rival makers almost had an accident during a lane-change maneuver on a street in Palo Alto, Calif., may be the most encouraging recent news to come from the growing effort to develop autonomous vehicles. The key word here is "almost." The fact is that they didn't actually have an accident.

What apparently happened is that two self-driving cars, both occupied by passengers in the drivers' seats but who were not actually driving, wanted the same spot in the same lane. A Google prototype, based on a Lexus RX400h hybrid crossover SUV, pulled into the line of traffic that the other car was preparing to enter.

The second car, a prototype Audi Q5 crossover SUV from auto parts maker Delphi, detected the lane change by the Google vehicle and aborted its own lane change until the lane was clear, at which point it also changed lanes. That's it. Had this happened while the humans in the cars were driving, the moves would have been totally routine.

As it happens both of the autonomous vehicles handled the situation exactly as they should have. There was no exchange of rude gestures or screamed obscenities. It was by all accounts a non-event other than the fact that they were driving in traffic on public streets. Now, writers in the non-tech media are seeing reason for concern.

A little context is probably needed. I live and work in the suburbs of Washington, DC. An event such as the one above would have been notable mostly because of the lack of gunfire or other murderous intent.

Were such an event to happen with human drivers on the Capitol Beltway, the drivers (likely lobbyists or Congressional staffers or both) would have gestured, shouted, taken photos with their phones all while ignoring the traffic around them. Then while still nominally driving their vehicles they would have uploaded the images to the local television stations along with breathless commentary.

I simply cannot wait for the day when only autonomous cars are allowed on the Beltway. I suspect the beleaguered commuters around Los Angeles and New York and other big cities feel the same way, but still there's concern about driverless cars.

When I hear about those concerns, I'm reminded of the times when I used to visit my mother's office. Mom was the advertising director for a big department store in my home town and I would take an elevator to reach her office.