San Francisco Power Outage Clamps Down on Waymo Fleet and City Mobility

A sweeping power outage in San Francisco has forced Waymo’s autonomous vehicles to halt mid-journey, triggering widespread traffic disruptions and exposing the fragility of urban mobility networks in the face of infrastructure failure. The blackout, sparked by a fire at a Pacific Gas and Electric substation, left approximately 130,000 customers without electricity and disrupted essential city services, prompting an urgent response from emergency management, transportation agencies, and local residents.

Historical context: this incident arrives amid years of rapid adoption of automated transportation in major urban centers. San Francisco, with its dense road network, high traffic volumes, and proximity to technology hubs, has become a focal point for pilots and deployments of self-driving taxis and shuttle services. The current outage underscores a recurring theme in modern urban life: the growing dependency on complex, interconnected systems—power grids, communications networks, transit operators, and autonomous vehicle platforms—that together shape daily movement. When one element falters, the ripple effects can cascade quickly through corridors that rely on synchronized signals, real-time data, and predictive routing.

What happened and the immediate impact

• The outage originated from a fire at a PG&E substation, affecting a broad swath of the city’s electrical grid and resulting in an estimated 130,000 customers losing power.
• Waymo’s self-driving fleet halted at intersections across San Francisco, unable to navigate without functioning traffic signals. The stoppage disrupted a significant portion of peak-hour traffic, straining arterials and neighborhood streets alike.
• Public transit experienced knock-on effects as Muni buses and BART services reported delays and diversions, compounding the city’s transportation challenge during the blackout.
• City officials urged residents to limit non-essential travel, treat intersections as four-way stops, and anticipate longer commute times as restoration efforts proceeded. Emergency responders coordinated with utility crews to secure affected corridors and restore critical services.

Economic implications and operational considerations

• Short-term productivity losses: The temporary immobilization of autonomous vehicles translates into lost efficiency for ride-hailing fleets and delivery services that rely on predictable travel times. Businesses dependent on timely freight and courier operations may experience delays, with downstream effects on customer satisfaction and service level agreements.
• Infrastructure resilience investments: The outage highlights the value of resilient power and transportation infrastructure. Municipal and state agencies may accelerate plans to harden critical nodes, deploy microgrids or distributed energy resources, and bolster redundancy in signaling systems that support autonomous mobility.
• Public transit knock-ons: When power outages interrupt subway-like regional systems and bus networks, congestion rises on non-electrified corridors, increasing fuel consumption and emissions as drivers seek alternative routes. This scenario reinforces the business case for diversified mobility options, including electric buses, micro-mobility solutions, and on-demand transit to mitigate single-point failures.
• Insurance and liability considerations: As autonomous platforms operate in dense urban environments, outages raise questions about fault, liability, and coverage during periods of system downtime. Operators and insurers may re-evaluate risk models to account for multi-system outages that disrupt routine service delivery.

Regional comparisons and broader context

• Metropolitan parallels: Major cities worldwide rely on aligned power, transport, and digital systems to support autonomous fleets. When utility outages occur, similar patterns emerge: sudden traffic disruptions, increased congestion, and heightened demand for manual traffic management. In cities with high penetration of smart signals and vehicle-to-infrastructure communication, the disruption risk is amplified if backup power ingresses are not robust.
• Lessons from past outages: Historical outages in urban centers have shown that diversifying energy sources for critical signal infrastructure—such as powered backups for traffic lights and transit hubs—can significantly reduce downtime. Regions that invested in resilient signaling and decentralized energy have demonstrated faster recovery and less disruption to mobility ecosystems.
• Economic resilience metrics: Cities that couple electricity resilience with adaptive traffic management tend to recover more quickly from outages. Measuring resilience through metrics like average time to restore critical signals, the share of autonomous vehicles able to resume service post-restoration, and commuter mode-shift rates can inform future investments.

Public reaction and social dynamics

• Community response to mobility disruption: Residents likely experienced frustration due to longer commutes, crowded transit, and the need to adjust routines. In parallel, the incident prompted a surge of real-time information sharing on social platforms, highlighting the importance of accurate, timely updates from city officials and utility providers during emergencies.
• Trust in autonomous technology during outages: Outages offer a real-world stress test for public confidence in self-driving systems. While drivers can assume manual control during power gaps, prolonged outages could influence public perception of the reliability and safety of autonomous fleets in dense urban environments.

Technical underpinnings and safety considerations

• Dependency on powered signaling: Autonomous vehicles rely on a functioning electrical grid to interpret traffic signals, receive real-time instructions, and coordinate with other road users. When signals fail, the safety protocols of many autonomous systems revert to conservative behavior, often leading to slower movement, cautious stopping, and a preference for human oversight in decision-making.
• Restoration sequencing: Utility crews typically prioritize critical infrastructure—hospitals, water treatment, and major transit corridors—to reduce cascading impacts. Transit agencies and technology providers coordinate with utilities to reestablish essential services, test systems, and validate safety before full-scale reintroduction of autonomous operations.
• Data and telemetry continuity: In outage scenarios, maintaining telemetry for fleet management becomes crucial. Operators may switch to offline or degraded modes, using preloaded maps and cached data to guide vehicles until normal connectivity returns. This transition underscores the need for robust failover architectures and redundant communication channels.

Recovery steps and ongoing efforts

• Power restoration: Utility teams are focused on isolating the cause of the fire, inspecting damaged equipment, and progressively restoring substation functionality. Restoration timelines depend on safety assessments, weather conditions, and the extent of infrastructure impact.
• Traffic management adaptation: City agencies deploy temporary traffic control measures, deploy portable signals where feasible, and coordinate with law enforcement to assist at critical intersections. Alternative routing guidance is disseminated through official channels to alleviate bottlenecks and reduce gridlock.
• Transportation network adjustments: Muni and BART operators implement contingency plans, including rerouting services, increasing frequency on certain lines where possible, and advising riders about delays. Partnerships with ride-hailing and micro-mobility providers may help bridge gaps while the electrical system is stabilized.

Longer-term considerations for urban mobility

• Redundancy and microgrids: Investments in distributed energy resources and microgrids near critical mobility nodes can limit outage duration. By ensuring backup power for traffic signals, transit control centers, and fleet charging stations, cities can sustain more continuity during outages.
• Enhanced signaling resilience: Upgrading traffic signals with robust battery backups and fail-safe modes can minimize disruption. Integrating autonomous vehicle software with resilient infrastructure supports safer, more reliable operation during power events.
• Public communication strategies: Transparent, proactive communication about restoration progress, safety precautions, and travel alternatives reduces confusion and fosters public cooperation during emergencies.
• Policy and governance: The incident may prompt policymakers to revisit emergency response protocols for autonomous mobility. Clear guidelines on how to handle autonomous fleets during outages help operators plan safer, more predictable responses when infrastructure systems are compromised.

Conclusion: navigating a power-dependent era The San Francisco outage affecting Waymo’s self-driving fleet reveals the interconnected vulnerabilities at the heart of modern urban life. As cities embrace automated mobility, the resilience of supporting systems—power, signaling, transit, and data networks—becomes a vital component of urban competitiveness and public safety. While restoration efforts are underway, the incident serves as a reminder that durable, adaptable infrastructure is essential to keep cities moving when disruptions occur. By prioritizing redundancy, transparent communication, and cross-sector collaboration, San Francisco and other metropolitan regions can better withstand future outages and maintain continuity in mobility, commerce, and everyday life.