How long is the broken center stripe on an interstate highway, and how long is the interval between stripes ?

a. 3 feet and 9 feet

b. 5 feet and 15 feet

c. 8 feet and 16 feet

d. 10 feet and 30 feet

Tom Vanderbilt writes that the U.S. standard is 10 feet, but that stripes may be as long as 12 feet or more —- longer, in fact, than the average car. The interval between stripes is to be three times the length of the stripe. So 12-foot stripes would have 36 feet of space between them.

"If you've ever broken down on a highway, being on foot is an odd experience," says Vanderbilt. "Even to be walking on an arterial, and standing next to a traffic sign or going up by a traffic light, I mean, they're huge. We whisk by them and they look like little things hanging in the landscape. I took this as an indicator of how skewed some of our perception is moving at speed."

So, how big would you say a traffic light is on a busy arterial road? Would you believe that the lens of each of the three lights is 12 inches in diameter, and the entire structure can be nearly 5 feet tall?