According to AAA, Americans spend on average 293 hours a year behind the wheel. With improved technology, cell phone signal is more important than ever when in the car. After all, we rely on our cell phones to make (hands-free) calls, help us find our way around thanks to Waze and Google Maps, stream music and even keep passengers entertained with streaming video.

To better understand cell phone signal coverage in the US, we drove 52,000 miles, covering 49 contiguous states, as well as Alaska. While on the road, we conducted 703,000 voice and data tests. As a result, we were able to show which networks had the pedal to the metal and which offered consumers a bumpy ride.

AT&T customers live life in the fast lane

Overall, we found that data performance was really different between the four largest operators (AT&T, T-Mobile, Sprint and Verizon). Our tests which emulated customers watching a short video clip, found that AT&T customers have the quickest download speeds at 6.9 Mbps, which is an impressive 33% faster than its nearest competitor, Verizon.

AT&T and Verizon customers also had the most reliable data services, with over 99% of the tasks we tested completing successfully. And when it comes to telling all their friends, colleagues and family about their road trips (or complaining about traffic jams), AT&T and Verizon customers also had the fastest upload speeds for tasks emulating social media posts.

Which network gave customers a bumpy ride?

When it comes to reliability, the road had some potholes for T-Mobile customers, as our tests pointed to a call success rate of 89% (the least reliable); whereas Verizon and AT&T had the highest success rates at 97% and 96% respectively.

Feeling nostalgic for AM Radio?

Our tests also found that Sprint had the least reliable data connection on test, with only 85% of tasks completing successfully. This means that drivers and passengers won’t be able to stream their favorite online music, sports or news channels 15% of the time.

In addition, Sprint customers might want to keep to the far right lane while driving, as its download speeds were closer to that of AT&T’s 3G network than they were to any of its competitors’ LTE network capabilities. It doesn’t surprise us at all that Sprint also relies on its 3G network more than the other operators.

There you have it – AT&T and Verizon consistently overtake Sprint and T-Mobile when it comes to overall network performance.

Want to see our full test results? Check out our press release!