Robocar impact on traffic congestion and capacity
Many people wonder whether robocars will just suffer the curse of regular cars, namely traffic congestion. They are concerned that while robocars might solve many problems of the automobile, in many cities there just isn't room for more roads. Can robocars address the problems of congestion and capacity? What about combined with ITS (Intelligent Transportation Systems) efforts to make roads smarter for human driven cars?
I think the answer is quite positive, for a number of different reasons. I have added a new Robocar essay:
In short, a wide variety of factors (promotion of small, single passenger cars, ability to reverse streets during rush-hour, elimination of accidents and irrational congestion-fostering behaviour, shorter headways, metering of road usage and load balancing of roads and several others) could amount to a severalfold increase in the capacity of our roads, with minimal congestion. If you add the ability to do convoys, the increase can be 5 to 10 fold. (About 20-fold in theory.) The use of on-demand pooling into buses over congested sections allows a theoretical (though unlikely) 100-fold increase in highway capacity.
While these theoretical limits are unlikely, the important lesson is that once most of the cars on the roads are robotic, we have more than enough road capacity to handle our current needs and needs well into the future. In general, overcapacity causes building, so in time we'll start to use it up -- and have much larger cities, if we wish them -- but unlike today's roads which add capacity until they collapse from congestion, advanced metering can assure that no road accepts more vehicles than it can handle without major risk of congestion collapse.
Even before most cars are robotic, various smart-road efforts will work to improve capacity and traffic flow. The appearance of robotic safety systems in human driven cars will also reduce accidents and congestion along the way. Free market economist Robin Hanson believes the ability of cities to grow much larger will be one of the biggest consequences of robocar capacity improvements.