Driver or passenger? Here's how Root makes the call

One of the most common questions we get asked here at Root is: how do we know whether you’re the driver or the passenger?

It’s a great question. We rate you based primarily on how you drive, so it only makes sense to wonder how we know that you're actually behind the wheel.

It all starts with your phone.

First, we collect high-frequency sensor data from instruments in your phone. We start collecting this data from the moment the car starts driving until your trip is complete.

And the instruments we use? They already exist in all of the smartphones we support. You actually use many of them already and may not even realize it.

Global positioning system (GPS)

Arguably the most familiar, you use it anytime you access popular apps like Google Maps or Apple Maps. In addition to latitude and longitude, your GPS collects data regarding your speed, altitude, and the direction that you're heading.
Global positioning system


Your phone's accelerometer detects the acceleration of the phone (a pretty good indication of movement, such as driving in a car).


Another sensor we use is the gyroscope, which you may have heard of before. You'll find them in other tech uses, but the one in your phone is used to help the accelerometer by collecting your rotation rates.


The magnetometer detects your phone's orientation in relation to the Earth's magnetic field (just like a compass).

We then take all of this data that we collect and put it into our super smart algorithms. Our algorithms use this data to accurately determine the motion of your phone. And that's what it all comes down to.

The motion of your phone is actually different when you're the driver of a car versus when you're a passenger.

So by using the data from these instruments and our algorithms, we are able to very accurately and confidently determine if you're behind the wheel or just along for the ride.

Okay, now you know how we can tell whether you're the driver.

But how do we know if you're even in a car?

Well, we are also able to use data from your phone to know if you are driving a car or are using another mode of transportation, such as biking, taking the bus, or riding the subway.

For example, if you're riding a bike, speed patterns will be different and you will have much slower accelerate and decelerate rates.

Trains have distinct rates of curvature, as do buses. And we can even merge the data we receive from your phone with a data set of train routes. All of this data informs us that you are not driving a car even though you are using transportation. (Pretty neat, huh?)

Now that you know we can accurately determine your rate based on your driving (and your driving alone), go ahead and download the app.

Download the app now

See how much you can save with fair car insurance.

Get new posts in your Inbox

Get the app

App store
Play store
ROOT for iPhone