Safety failure
Realized harm
Driverless Waymo vehicles honked at each other all night in a South of Market lot, an emergent multi-agent interaction with no humans aboard
AIR-2024-0033 AIR record · 2024-08-waymo-soma-parking-lot-honking
A real party was affected. This incident caused actual consequences, not a demonstrated capability.
From the supporting source
No one is inside the cars, and they appear to be automatically reacting to each other's presence.nbcbayarea.com
The record
Disclosed
2024-08-13
Occurred
2024-08
Vendor
Waymo (Alphabet)
Product
Waymo Driver
Risk domain
Tool misuse › Uncontrolled resource consumption
System type
Classical autonomy (no generative model)
Who acted
Agent acted — the vehicles actuated their horns all night
Attack surface
Autonomous operations
Autonomy level
Fully autonomous
Initial vector
None autonomous action
Impact type
Service disruption
Confidence
High
Submitted by
EAI Internal
Crosswalk
- OWASP Agentic Top 10 (2026)
- ASI02 – Tool Misuse and Exploitation
- MITRE ATLAS
- AML.T0029 – Denial of ML Service
- NIST AI RMF
- MAP 3.2
- EU AI Act
- —
- ISO/IEC
- TR 24028; 42001; 23894
- AIUC-1
- D. Reliability
- Scope
- tool failure
- Mitigation
- Impose rate limits, timeouts, and resource quotas on agent actions.
- Taxonomy
- Enkrypt AI agent risk taxonomy · Black-Box Red Teaming of Agentic AI: A Taxonomy-Driven Framework for Automated Risk Discovery
Blast radius
South of Market residents in San Francisco high-rises, nightly for several weeks
Capability abused
Defense & remediation
Recorded defense
none; behaviour was within each agent's normal policy
Guardrail kinds
None
Guardrail outcome
Not applicable
Fix shipped
Waymo acknowledged and worked on a fix after weeks of complaints
Taxonomy & references
Curator notes
The cleanest emergent-multi-agent record in the corpus. Every individual agent followed its policy correctly; the harm existed only in the interaction between them, at a time and place no human was present to notice. Nothing in the system was watching for a bad collective outcome, and the feedback path was neighbours calling a TV station. AI Incident Database incident 794.
Supporting sources
Cite as
Enkrypt AI. "Driverless Waymo vehicles honked at each other all night in a South of Market lot, an emergent multi-agent interaction with no humans aboard". AIR, AIR-2024-0033. https://agentincident.vercel.app/i/AIR-2024-0033/ (accessed 2026-10-19).