Although Uber's review system allows both riders and drivers to submit feedback on a recent journey, it can be hard for the company to know what really happened. Did a driver constantly break the speed limit or was a customer totally unfair with their feedback? Without evidence, it's simply one person's word against another's. Uber has a plan to change that, though. Using gyroscopes and GPS chips built into driver and passenger smartphones, the company's new scheme will log when a driver is (or isn't) driving dangerously. Feedback will still be welcome, but the idea is to back up words and scores with cold hard data.