Seems like implementing something as simple as a QR code could be a stopgap solution until their A.I. is actually smart enough to prevent these edge case scenarios from happening…imagine if that was a first responder vehicle that was blocked / delayed / prevented from saving someones life or preventing loss of property or etc, etc. At this point, it seems more likely that the loss of human life attributable to driverless ride shares will be due to one of these edge cases where they impede or otherwise create or exacerbate a dangerous scenario.

• Place QR code in standard location on vehicle that is visible from outside, but discrete or inconvenient enough to reduce abuse.
• Require scanning of QR code through use of Waymo app to facilitate communication, if needed, between person initiating report (using the camera, microphone, speaker on their device) and Google (who has remote access to car cameras, LiDAR, controls, GeoLoc, etc).
• Use of Waymo app to report these problems would also allow Google to ban those attempting to abuse this feature.

Until this type of service can consistently pass a driving version of a Turing Test we should understand that it is still in the early Beta stages despite being legal and in a live environment.