Alphabet’s Waymo said on Thursday it has suspended its robotaxi service on freeways in the United States and paused its operations in Atlanta, Georgia, as it updates software to improve performance around construction zones and flooded roadways.

The suspension comes as Waymo, which has been growing its robotaxi operation slowly and steadily for years in the U.S., has quickened the pace of expansion, as others, including Tesla and Amazon’s Zoox, step up their push in the sector.

“We have temporarily paused freeway operations, as we work to integrate recent technical learnings into our software and expect to resume these routes soon,” a Waymo spokesperson said in an email.

Freeway trips on Waymo were available in San Francisco, Los Angeles, Phoenix, and Miami.

Waymo was evaluating and improving its performance around certain types of construction zones, the company told Reuters, adding that street operations remained unaffected.

The company also paused its service in Atlanta, offered through its partnership with Uber, it said, after an unoccupied Waymo robotaxi stopped in flood water on Wednesday.

The pause follows Waymo’s recall of about 3,800 robotaxis in the United States earlier this month, after identifying a risk that vehicles could enter flooded roads with higher speed limits, raising safety concerns.

(Reporting by Abhirup Roy in San Francisco and Nathan Gomes in Bengaluru; Editing by Shilpi Majumdar)