The crash

For years, insurance companies have used estimates of your annual mileage to determine your car insurance rates. But with recent changes in technology, insurers now have an unprecedented ability to judge your actual driving habits. Armed with detailed data on how often you slam on the brakes and what times of day you're on the road, insurance companies are increasingly relying on precise, technological means of assessing risk and using that information to set your monthly premiums.

Liberty Mutual, the country's third-largest property-and-casualty insurer, took the latest step in that direction Monday when it announced a partnership with Subaru. Beginning later this year, Subaru drivers who have paid for the automaker's Starlink infotainment system will be able to download an app to their cars that notifies them when they are accelerating too aggressively or breaking too hard.

The app is part of Liberty Mutual's program, which gives drivers a 5 percent discount on their rates for enrolling and additional discounts up to 30 percent for heeding the apps guidance on driving safely.

https://www.washingtonpost.com/news/the-switch/wp/2016/01/04/the-big-data-of-bad-driving-and-how-insurers-plan-to-track-your-every-turn/