The Washington State Patrol plans to utilize cell phone data to identify parts of the road that are high-risk for speeding. Once spots are identified, the agency will deploy additional troopers to monitor those stretches during times of higher traffic.

The data that the Washington State Patrol purchased from a company called Michelin Mobil does not yet track real-time movements, according to the agency, as it only includes records of when and where drivers most often brake, accelerate their vehicles, and use their phones.

The agency stressed that they do not have access to any other personal information.

Sergeant Greg Riddell said that information related to driving behavior “is really the only data we take from that information source. All the other stuff is redacted. We don’t have people’s personal information, so hopefully people aren’t thinking it’s a big brother thing, it’s certainly not that.”

A somewhat conflicting message comes from the acting director of the Washington Traffic Safety Commission, Shelly Baldwin, however. She attested that the Washington State Patrol is collecting cell phone data “to really build this huge database of information that comes directly, real time.”

The data collected thus far derives from over one million cell phone users in Washington state. It is not clear whether such users are limited to residents of Washington state or include all drivers who traveled through monitored areas.

While law enforcement agencies have long used individual cell phone data, obtained from providers with a warrant, the use of mass cell phone data, extracted from Americans without their consent and without any due process, raises potential civil liberties concerns.

The ACLU has not yet weighed in on this particular Washington state enforcement effort, but the group has done extensive legal work to protect Americans’ cell phone data from government overreach.

“We advocate in courts, Congress, and state legislatures to make sure that law enforcement is required to comply with the Fourth Amendment’s warrant requirement before obtaining cell phone data from service providers or tracking phones directly using Stingray devices, also known as “cell site simulators,” reads the ACLU’s cell phone privacy page.

The priority for using this data, Riddell added, will be routine traffic enforcement.

“The biggest thing we’re looking for in this emphasis is obviously zero tolerance for 15 miles an hour over the speed limit, distracted driving.”