Waymo’s fleet of self-driving vehicles in the United States have driven more than 10 million miles on public roads, the company’s chief executive John Krafcik announced in a Medium post.

Alphabet’s self-driving car division has prototype testing in 25 cities across the United States, including states such as California, Arizona, and Michigan and cities like Los Angeles and San Francisco.

In addition to all of Waymo’s testing on public roads, it will also surpass 7 billion miles of driving in its advanced simulators by the end of the month. Waymo says that its simulations can recreate many rear-world scenarios and also create even more challenging situations to accelerate the development of its autonomous vehicles.

Moving forward, one of Waymo’s biggest goals is to deploy an autonomous ride-hailing fleet across the United States. The technology company currently operates a pilot program within the Metro Phoenix area, where over 400 participants can take rides in Waymo-operated vehicles. In the future, Waymo will introduce similar programs through the country.

Current Waymo prototypes have been programmed to be cautious and courteous, but Waymo says it aims to strike a balance between this and being assertive enough to make maneuvers you’d expect to see from a human driver, like merging lanes in fast-moving traffic.

“Our cars are designed to take the safest route, even if that means adding a few minutes to your trip. We value our riders’ time, and with even more experience and feedback from people in our cars, we’re working on ways to make our routes, pick-ups and drop-offs even more efficient,” Krafcik added.