Back in the '90s, when cell phones were becoming all the rage in New York City, a courtesy code developed about their appropriate use.
New York, like Japan, is a densely populated living space, and selfish activities that make life more tedious for the general population are quickly frowned upon, the perpetrators ostracized. There is a code, and it is understood that sticking to the code is what makes the city livable.
Most New Yorkers, at least those who wanted to have friends, learned that talking loudly on a cell in a restaurant would attract rude stares, and often an impolite word or two from table neighbors. The same was true in enclosed spaces like doctors' waiting rooms, where sometimes an involuntary witness to a phone conversation would simply begin reading his newspaper or book out loud to the point where the phone user had to either hang up or leave the room.
What is needed with this texting fad is a sense of shame. Outlawing texting while driving is fine, up to a point--but it's hard to enforce. Mothers Against Drunk Driving managed to accomplish the stigmatizing of an activity. Before they came along, it was hard to convict drunk drivers because juries were sympathetic. "There but for the grace of God go I," and all that.
Americans love to do what is bad for them, especially if it makes them feel good. Take smoking, for example (the analogy is appropriate, because we're talking about addictions that also happen to be harmful to others). Only when driving texters are figuratively "driven out of the building" to stand in shame in the rain--the way smokers are--will the destructive behavior diminish.