There are many proposed solutions to traffic congestion in metropolitan areas. one solution has been prove ineffective: in fact, it promotes more cars and drivers on the roads. which solution is it? a) automate the driving process itself. b) build more infrastructure including more roads, tolls, and car-pooling lanes. c) using wireless vehicle-to-vehicle communication, cars could talk to each other in an attempt to keep traffic flowing more smoothly. d) a smartphone app that works like a social network for drivers, combining online maps with updates from other drivers about traffic jams, road works and accidents.