In a new update to its app announced Monday, Uber drivers will now be forced to take a six-hour break after a total of 12 hours of driving time. Drivers will not be able to accept new riders during that rest period.

In a blog post, the company said it will “strengthen our approach to help keep riders and drivers safe on the road while preserving the flexibility drivers tell us they love.” The post added that 60 percent of its drivers are only on the road for 10 hours or less per week.

By contrast, federal regulations stipulate that bus drivers may only drive 10 consecutive hours after having had eight hours off duty.

However, there is nothing stopping an Uber driver from driving 12 hours and then immediately switching to Lyft to keep working. (Many drivers work for both companies, often toggling between the two.) Lyft, however, already sets a mandatory six-hour break for every 14 hours of driving.

Some states have separate rules, which the app will also take into account: for example, Virginia imposes a maximum of 13 hours of driving during a 24-hour period.

Uber did not answer Ars’ question as to how many drivers work more than 12 hours at a stretch.

“I don’t have any data to share today on that,” wrote Susan Hendrick, an Uber spokeswoman, in an email to Ars. “But even one crash is too many, as recent reports suggest. It’s an issue for all who share the road. We want to encourage people to use Uber responsibly.”