I drove behind one yesterday as it returned to Google HQ in Mountain View. It was pretty exciting. It was also rush hour, and people didn't like that it tried so hard to give a safe amount of space in front and behind itself - it ended up being a little bubble of lane-changing space that moved slower than the rest of traffic.
Not that I hold any of this against the car - it was clearly doing the intelligent thing. But people... we are animals.
Weird. Your post didn't have a reply link. I had to click the permalink for it.
Anyway, I wanted to say that I read an article about a guy in Seattle that always kept a couple car lengths ahead of him. I seem to remember the article saying he was able to get home quicker that way than by behaving like the rest of the cars on the road.
Meta: there's a delay between when a comment is posted, and when the reply link becomes active. That delay is larger for deeper comment threads. I've never heard an official explanation, but one can imagine a few reasonable ones, e.g. to encourage people to stop and think in heated back-and-forth exchanges.
I too live in the Seattle area, and I've heard of this technique. Sadly, when implementing it, all you see is the angry drivers behind you who rush to pass and gobble up the traffic bubble you've been saving.
- if truckers can maintain a bubble, how can it be impossible?
- yes, aggressively weaving drivers sometimes jump in ...then they jump out again.
- at merge zones, the entire point is to let people into your lane.
- In theory, everyone else wants your precious bubble. In practice, not.
...and in a burning building, we all know the best way to escape, eh? EVERYONE AGGRESSIVELY PUSH FORWARD, DON'T LET ANYONE ELSE GET PAST, COOPERATION AND TEAMWORK ARE FOR LOSERS! Yep, that certainly won't trigger a huge clogged mess where everyone dies.
Seems like the safe distance in front of a robot car would be significantly less than for that of a car driven by a human. Of course, most humans I know think that the safe distance is 2 feet, which is probably less still.
They probably have to assume the human co-pilot may still need to assume control and avert disaster, and give them enough extra time to do that (beyond the time they'd need after starting out in control). With no need for failover, the robot should reliably react faster, though it's probably only reacting to immediate events rather than predicting drivers' (mis)behavior.
Most people stay way too close to the car in front, though. You're doing well as long as nothing unexpected happens. But if someone for some reason has to hit the brake really fast, you'll get a completely unnecessary pileup.
The Google cars probably also have additional margins of safety to allow for the driver to react to unexpected computer behavior _and_ actually step in and perform the maneuver himself.
I've seen the Google self-driving car navigating within morning traffic in San Jose. There were two men with laptops in the driver and passenger seats, presumably monitoring the car and available to step in if something went wrong. It was also kind of surprising to see the roof-mounted device it used to map its surrounding. It was fairly large and rapidly rotating.
To date, all Google autonomous cars have had two occupants - a driver (who is strictly hands-off - she's only there in case something goes wrong) and a tech who monitors the data to make sure things are proceeding as expected.