WaPo:

Clicking upward at a rate of one person every 11 seconds, the U.S. population will officially surpass 300 million in the next week or so.

The milestone is a reminder that the United States remains a remarkable demographic specimen, 230 years old (since the Declaration of Independence) and still in a growth spurt. Read on...

Oy. So that's why the freeways are so backed up.