By most accounts, Uber makes a pretty nifty app, but its latest feature — monitoring acceleration and braking — isn’t sitting well with its drivers.

Uber announced the forthcoming features in its driver app this week, ahead the Fourth of July weekend — a time when car accidents and fatalities typically surge.

The app will make use of gyrometers in most smartphones to track small movements, which could be used to determine if a driver speeds or applies the brakes suddenly. Unsafe driving habits would be detailed to drivers in daily statistic reports, and, in the case of speeding or sudden movement, the app could display alerts in real-time.

Such tracking had already been taking place — without drivers’ knowledge — in Houston; now Uber plans to roll out the feature in new versions of the app in 11 more cities, with more to come.

Uber contends that the tracking features are essentially an extension of the GPS monitoring that drivers already consent to when they sign up as “partners.”

In addition to privacy concerns, the feature could lend ammunition to Uber critics who say its drivers are treated less like contractors — as Uber insists — and more like employees, since the monitoring of driving habits can be seen as a kind of “discipline” against them. This issue has been central to class-action lawsuits brought against Uber.   

Several Uber drivers decried the new features in internet forums.

“Now they’re monitoring my speed & braking? Get Out Of My Business Uber. Or, pay me a salary, sick days, advertising fees, vacation pay, bonuses, on & on & on,” said one commenter on

A commenter on the Uber driver reddit forum questioned how accurate the new feature would be: “Great, I can see it now, tons of drivers deactivated because their phone falls out of the holder and bounces on the floor. Now Uber thinks I was in an accident because of the app seeing that.”

However, another driver on noted that Uber would use the data to confirm — or debunk — complaints about poor driving habits: “For drivers wary of being monitored to that degree, this might seem like the start of something more sinister. But so far the company has used this to benefit drivers by making sure they’re not negatively affected by rider feedback that could not be verified by empirical data.”

Uber, for its part, insists that new features are all about safety.

“We believe that by providing people with more choices, we can help them make better decisions; and by using new technology we can improve safety for everyone on the road. Have a safe and happy Fourth of July,” the company said in a statement.