DoorDash will start surveilling delivery workers' driving with an app that tracks how hard they are braking and accelerating

• A new feature on the DoorDash app tracks how often its workers break or accelerate suddenly.
• The information will be available to dashers through "Driving Insights," the company said Friday.
• It's one of several changes that DoorDash has made to its app in recent months.

DoorDash is now keeping track of how often some of its drivers break or accelerate suddenly, it said Friday.