Imagine being able to see around corners to know that someone has just braked really hard up ahead
or swerved lanes? Waze could collect acceleration data and use it as an early warning to cars behind.

The DriveScore app uses the same phone accelerometer data to provide personal driving style feedback to the owner. But wouldn't it be so much better to share it with the cars nearby?

As an example, if every driver in lane 3 of a motorway is slowing, changing lanes then speeding up again at the same static location, there will likely be a common cause for the acceleration changes, such as a stranded vehicle, accident or other obstruction. This was the case for me at Christmas when on a tight bend connecting 2 motorways I came across at accident in lane 2 and had to swerve to avoid it, as did everyone behind me. If only my phone could have warned those behind.

Even in good traffic, by combining the same detailed GPS and accelerometer data from multiple cars, Waze would be able to identify common patterns in speed and acceleration, such as vehicles changing lanes at the same a relative point along a motorway which would indicate that there is a slow moving vehicle ahead.