This is 99% invisible. I'm Roman Mars.

I want you to conjure an image in your mind of the white stripes.

Not those white stripes, but the white stripes that divide the lanes of traffic going in the same direction on a major highway.

How long are those stripes?

You can spread your arms out to estimate if you want to.

Over the course of many years a psychology researcher named Dennis Schaefer at Ohio State

asked students from many different parts of the country this question. And the most common response was two feet.

So if you're like most people, you estimated that those white stripes are two feet long,

maybe a little more.

But if you did, you'd be very, very wrong.

This is Tom Vanderbilt.

My name is Tom Vanderbilt.

I'm a writer in New York and author of Traffic,

Why We Drive the Way We Do, and what it says about us.

Every three pages of Tom's terrific book, Traffic, I could probably turn into a 99% invisible episode,

but back to the highway.

Well, early on in my research, I was talking to a highway. Well early on in my research I was talking to a highway

engineer and he said if your car is ever broken down on the side of the road.

We've ever been forced to get out of your vehicle on a highway. Just take a moment to notice what a strange landscape it is.

If you're having to be standing near a road sign,

these road signs are huge.

I mean, they're not meant to be experienced as humans on foot they're meant to be

...