RobotRisk Autonomous Systems Incident & Risk Register
RobotRisk / Tier IV Inc. (Umi no Mori Park shuttle bus, Koto City government demonstration) / 2026-02-27
other · malfunction

Koto Ward autonomous shuttle bus accident traced to route-deviation detection failure

S1 · 02/27
2026 · 16:19 · Tier IV Inc. (Umi no Mori Park shuttle bus, Koto City government demonstration) · Koto, Tokyo, Japan

Record

CompanyTier IV Inc. (Umi no Mori Park shuttle bus, Koto City government demonstration)
Categoryother
Typemalfunction
Date02/27
2026
Time of day16:19
LocationKoto, Tokyo, Japan
SeverityS1 (near-miss / disclosed vulnerability)
Scale1 bus
Confidencemedium
VerificationYes - adversarially checked against the cited source
SourceLOGISTICS TODAY

What happened

A Level-2 autonomous shuttle bus (Tier IV Minibus 2.0) operating at Umi no Mori Park in Koto Ward, Tokyo struck a median curb on 2026-02-27 after a manual lane-change during automated operation caused the route-deviation detection program to fail silently. No injuries or other traffic disruption occurred.

Tier IV Inc. (Umi no Mori Park shuttle bus, Koto City government demonstration) record context

Tier IV Inc. (Umi no Mori Park shuttle bus, Koto City government demonstration) vs other alternatives

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14282017 S1: 12017 S5: 12172019 S3: 11192021 S3: 11212022 S5: 11222023 S3: 12023 S4: 23232024 S1: 22024 S2: 42024 S3: 32024 S4: 72024 S5: 521242025 S1: 12025 S2: 72025 S3: 62025 S4: 82025 S5: 628252026 S1: 12026 S2: 92026 S3: 32026 S4: 22026 S5: 31826
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