What just happened? Uber's RideCheck, one of the safety features it announced over a year ago, has been released for all drivers and passengers in the US. The system uses smartphone sensors to detect if anything is out of the ordinary, such as an unexpected or sudden stop, or if a vehicle is taking an unusual route, and sends notifications asking if everything is okay.

Back in September, Uber announced several new safety-focused features, one of which was RideCheck. It uses a smartphone's GPS, accelerometer, gyroscope, and other internal sensors to detect potential crashes automatically.

If the system's algorithms detect an irregularity, both passenger and driver will be sent an alert. Recipients can then bring up a panel and use the app's emergency button to call 911. There are also options to call the Uber safety line, report a crash, or confirm that the car stopped on purpose, and users can change their destination or share their trip with a friend.

Uber's safety team may follow up the notification with a phone call. The company says that in the event of a crash, it can help expedite the insurance claims process.

Uber has spent the last 12 months testing RideCheck with select riders in several US cities, including Los Angeles and Dallas.

Uber's head of safety products, Sachin Kansal, writes that RideCheck's technology will continue to evolve, and the firm is working on adding additional scenarios to the system.