LO
PilotDriving & mobility2023-12-10
A four-month evaluation of the Treasure Island "Loop" autonomous shuttle pilot in San Francisco recorded its on-board attendant taking manual control 358 times and deploying a wheelchair ramp 18 times
Bus driveroccupation page →
Event date / reported
2023-12-10 · reported 2024-06-25
Evidence stage
PilotSmall-scale trial in a real setting. Tells us the deployment conditions are being tested, not that they hold — so one pilot is never enough on its own; two independent ones are.
Tasks this bears on
Getting people on and off safely
Lowering the ramp for a wheelchair or a pram, waiting for the slow boarder, checking the doors, answering the question at the front.
Being augmented✓ Evidence-backed
Watching the bus drive itself
Sitting in the driver's seat of an autonomous bus, not driving it, ready to take over when it hesitates or errs.
New task✓ Evidence-backed
Where this applies
The Treasure Island Mobility Management Agency's own final evaluation report (a joint powers agency formed by the San Francisco County Transportation Authority, the Treasure Island Development Authority and the San Francisco Municipal Transportation Agency), funded by a USDOT/FHWA Smart City grant, an MTC grant and local Prop K sales-tax funds. It covers one closed pilot on Treasure Island, San Francisco: three Level-3 shuttles operated by Beep with GMM (formerly Navya) vehicles on a fixed route from 16 August to 10 December 2023, each carrying an on-board attendant/safety driver at all times. The report's own operations and accessibility sections give the attendant's tasks in counts, not a plan: 358 disengagements over the four months, where the vehicle handed control to the attendant, most often because another road user or an object was detected in the shuttle's path, or because the 5G/GNSS/RTK signal was lost; and 18 ADA ramp deployments plus 5 wheelchair securements to board passengers. occurredOn is dated to the pilot's last day of revenue service (10 December 2023), since every count above is a total across the whole evaluated period; reportedOn is the final report's own publication, dated June 2024 on its cover and 25 June 2024 in the file's own path. This is a different country, operator and regulator (the US National Highway Traffic Safety Administration and the California DMV, not Singapore's Land Transport Authority or Japan's transport bureau) from the two pilots already on this page, so it stands as an independent record rather than a restatement of them. It also cuts against reading this cleanly: in one incident the shuttle detected another vehicle running a stop sign and braked, but the attendant did not engage the emergency-stop button before a low-speed, no-injury collision. The pilot ended early, on 10 December 2023, because remapping the route around changed road conditions was cost-prohibitive for the agency to fund again — the report frames this as an operational and funding limit, not as a finding that the attendant role could be removed.
What this means
A public transit agency's own operating log of an autonomous shuttle shows what an on-board safety attendant actually did over four months, not what a plan says one would do: the vehicle handed control back to a human 358 times, most often to steer around a detected vehicle or object or to recover from a lost signal, and the attendant lowered a wheelchair ramp by hand 18 times and secured a wheelchair 5 times.
What it does not yet show
It is one small island pilot, not a network, and it ended after four months. It does not say how many attendants a city-scale service would need, and one incident shows the limit plainly: the attendant did not press the emergency-stop button in time even though the vehicle had already detected the hazard.
What you can check
Ask your own transit authority's newsroom or board minutes for the word "disengagement," and see whether it publishes a count for any autonomous pilot it has run.
Does it change the assessment?
No. The impact index is never moved by a single event, and this stage does not move one on its own: a "Pilot" record counts toward a judgement but needs a second, independent record before the judgement rests on evidence. This one is counted; on its own it changed nothing.
Source
Treasure Island Mobility Management Agency — The Loop Final Evaluation Report · verified 2026-09-24 · VOLO agent loop · interpreted 2026-09-24 · VOLO agent loop
Primary source — published by the party that did this, or the authority of record. No co-signature needed.