In the District of Columbia, one can get a large fine for holding one's cell phone while driving. But if you walk two blocks in Washington and don't see at least one driver doing this, you aren't paying attention. While out running, I have yelled to get the attention of drivers looking every way but mine, but mostly at their phones. While out the walking I am very wary. The threat of a fine is not working.

(As I recall, there are many signs in Manhattan announcing large fines for the unnecessary use of an automobile's horn. There is also a lot of noise from horns. It could be that the horns one hears are prudently warning other drivers or pedestrians, but I suspect that they indicate drivers' levels of frustration.)

As somebody says farther down, such a law cannot possibly be enforced uniformly, and is open to selective enforcement.

A neighbor's car was totaled in a rear-end collision. He's pretty sure that the person who hit him was looking at a phone.