SAN FRANCISCO, United States (AFP) — Waymo announced Monday that it had relaunched its robotaxi service in San Francisco after parts of its fleet became paralyzed at intersections during a massive power outage over the weekend.

The subsidiary of Google-parent Alphabet had to suspend operations Saturday evening when a fire at an electrical station left about a third of the city without power.

Waymo’s white Jaguars, equipped with cameras and sensors, have become a familiar sight on San Francisco streets.

With traffic lights out, many of the self-driving vehicles froze at intersections, creating major traffic jams. Videos on social media showed clusters of the confused autonomous cars stuck at crossroads.

“We resumed ride-hailing service in the San Francisco Bay Area on Sunday,” a Waymo spokesperson said in an email to Agence France-Presse on Monday.

The company said its cars are programmed to treat non-functioning traffic lights as stop signs, but the scale of the outage caused vehicles to remain stopped longer than usual.

Waymo then decided to temporarily suspend service for safety reasons.

The breakdown immediately drew mockery from Tesla CEO Elon Musk.

Tesla’s Full Self-Driving technology claims to operate independently of infrastructure, navigating with only cameras and artificial intelligence that adapts in real time — though vehicles still require a driver present.

Waymo has favored a more cautious and expensive approach, relying on multiple onboard sensors and complete mapping of areas where its fleets operate.