Exactly the technology that is being considered is fairly important when we discuss the results of experimentation about new technologies. For example, I think driverless cars are going to be just great. But that doesn’t mean that this particular method by which they will reduce congestion is correct.
Driverless cars could speed up traffic flow and journeys by one third
Well, they might, but it won’t be for this reason:
Fleets of driverless cars on the roads could speed up traffic flow and cut journeys by a third, even for people who are not using them, a Cambridge University study suggests. Researchers programmed 16 miniature robotic cars to drive around a two-lane track and observed how the traffic flow changed when one of the cars stopped. When the cars were not driving co-operatively, any vehicles behind the stopped car had to stop or slow down and wait for a gap in the oncoming traffic, as would typically happen on a real road. A queue quickly formed behind the stopped car and overall traffic flow was slowed.
But when the cars were communicating with each other and driving co-operatively, as soon as one car stopped in the inner lane, it sent a signal to all the other vehicles. Cars in the outer lane that were near to the stopped car slowed down slightly so that vehicles in the inner lane were able to quickly pass the stopped car without having to stop or slow down significantly, and improving traffic flow and therefore journey times, by 35 per cent. And even when a human-controlled car was put on the track with the autonomous cars and moved around in an aggressive manner, the other cars were able to give way to avoid the aggressive driver, improving safety.
That’s not driverless cars, that’s networked cars. Sure, thy’re associated technologies, we’re likely to have both. But they are still different techs.
The difference is that driverless is, well, no human driver. The car is navigating and functioning on its own. The second is that it is networked into and communicating with the cars around it. They’re not the same thing at all. It’s possible for each driverless car to be entirely autonomous, all of them working on their own sets of sensors etc. Or we can indeed get them all talking to each other.
Driverless cars themselves I think unlikely to speed up journey times. Much more important is that they’ll make journey times less important. If you’ve not got to drive, thus can play, read, or sleep, then journey time itself is less important, no?