This study is the first to assess which types of behavior contribute most to crashes and near crashes.

The aim of our study was to be able to attach a number to human traveling behavior. If you want to understand how modern epidemics spread, you need to make some assumptions about how humans spread.

All of these activities are much more dangerous than we thought before.

We're spending a lot more time in our cars commuting, and we're doing a lot more in cars, especially with new technologies. We do a lot of things and we don't get caught. But in fact we're just lucky and we get complacent.

It was far more prevalent than we expected, certainly during the daytime.

To the everyday driver, we'd like to say that, anytime you're engaging in something else while driving, that really does increase your crash risk by two to three times.