Uber has introduced new driver hours policies in the UK and U.S. to help prevent drowsy driving.

The UK policy requires a licensed driver on the app to take an uninterrupted 6-hour break after 10 hours of time on a trip with a passenger or on their way to pick up a passenger after confirming a trip request. Drivers who do not take a long enough break will not be able to log in to the app and take trips.

Drivers in the U.S. are required to take a 6-hour break after 12 hours of driving time, although different limits apply in some cities due to local regulations.

Uber says the move will strengthen its approach to help keep riders and drivers safe on the road while preserving flexibility for drivers.

“Licensed drivers who use our app really value the freedom and flexibility to choose if, when and where they work,” said Andrew Byrne, Uber’s Head of Policy in the UK. “And while drivers only spend an average of 30 hours a week logged into our app, we want to do our part to ensure they don’t drive tired.

“That’s why we’ve been sending drivers regular reminders to take rest breaks and why we’re now bringing in these new limits. On top of features like GPS tracking of every trip it’s another example of how Uber uses technology to help enhance driver and passenger safety.”