You'll have seen pictures of the "concept cars" of the future; driving without you or anyone else behind the steering wheel. Cameras, global positioning devices and computers do all the work. Just sit and relax, read the newspaper, tap on your i-something, or simply take a nap.
We aren't quite there yet, but Google and others are feverishly trying to make that vision happen. As M. Waldrop reports in Nature "This summer people will cruise through the streets of Greenwich, UK, in electric shuttles with no one's hands on the steering wheel--or any steering wheel at all."
From my perspective, whether you are sitting in a city commuter bus with 50 others, in a street car with 200 or a train with 1,000 more passengers on board is rather immaterial. These vehicles all proceed on pre-determined paths, especially the ones on rails. Currently, each has a driver regardless of size or number of passengers. You may meet the bus or streetcar driver but few would recognize the subway operator or the train's conductor. In fact, you might not even be sure if there is one in the train at all. So, the step-up to a driverless vehicle is minimal. What then is the difference between sitting in a commuter train or a car?
In the train you actually can stand up and stretch your legs, or even go to the facility but no car gives you that freedom and comfort. If I have to commute between downtown X and downtown Y, given an adequate schedule of operation, speed and transit time, then the train is certainly the better choice. That raises the question of more complicated commutes like from the periphery of one city to that of the other. Google's driverless cars have the answer to that as well; meet the complete mapping in high-definition of every pothole on each street.
Potholes are only one aspect of the problem. Perhaps you like to read an example from my own experience on how well that works--or not: A few years ago I rented a car with the latest GPS system to drive in Germany. As it so happened, I was quite familiar with the road I traveled on and really didn't need the GPS. As it also happened, the good burgers had recently built a new bridge over the local river, slightly offset from the old one but that information had not yet been entered into the road map system. That was quite upsetting to the "GPS-lady." She insisted that I "turn around immediately" while crossing the new bridge. The poor lady must have had a fit thinking that I was about to drown before her "eyes."
Now, just imagine your driverless car's high-definition GPS system also needs accurate on-time information on each pothole, change in curb location (if there is any) and other minute details of road condition, traffic, obstacles, children playing and everything else one could not possibly foresee and have a pre-programmed response for it.
I'm not saying that it would, just technically, be impossible to do so. However, the effort required to update all that information, on a real time basis, does not appear to justify the cost. Even if it would work for some major roads in sunny and dry California, it could not possibly work everywhere else or all the time, like in the blizzard we had a few days ago. The curbs had disappeared in snow drifts and it was hard to know what was ground or air.
When you can afford to stay home during blizzards, it's definitely "the better choice." However, if you commuted to the Big Apple in the sunny morning and then have to rely on your driverless car to get home in a blizzard, that GPS cannot receive a signal due to the atmospheric disturbance and your roof-top camera is plugged with snow but needs to be able to see the curb and rely on satellite navigation, you'll be in a tough spot.
When the wind is whipping a wall of snow in a horizontal direction and the GPS signal is completely attenuated by the stuff in the air between the satellite and your car, it's time to take matters into your own hands and hang onto the steering wheel--provided there still is one at all.
Alternatively, if you can wait long enough, spring and summer will arrive in due course.
