Lime scooters have been recalled in Switzerland and cleared off the streets of New Zealand following a string of injuries, including multiple broken bones, caused by a software bug that brings the scooters to an abrupt halt, throwing their riders off (the scooters are still available in the USA despite an account of a similar incident in Texas).
The company says it has found the bug: "[I]n very rare cases—usually riding downhill at top speed while hitting a pothole or other obstacle—excessive brake force on the front wheel can occur, resulting in a scooter stopping unexpectedly."
There's an important underlying issue here that illustrates one of the ways in which devices whose rental terms are enforced by software do not fail safe: Lime scooters are designed so that they can be remotely immobilized, over the internet, if your credit runs out or if the scooter is doing something else the company disfavors.
This design constraint means that the users of the scooter can't (in some circumstances) override the brakes. Malicious code, or code with errors in it, poses a constant risk for the scooter rider, because if it triggers this braking function, then by design the system will treat attempts by the rider override the immobilization command as an attack.
In an ideal world, we'd design the control systems for devices that can harm their users to fail safe, with overrides for owners that let them judge when safety features are inappropriately triggered. But when the "safety" that these features ensures is the safety of a rental company, not the user of the device, then the "fail safe" mode is one that elevates the protection of the owner's capital investment over the user's physical wellbeing.
This is bad enough in scooters, but in cars it's potentially lethal. It's also the most rapidly proliferating model of embedded systems design, as "software as a service" metastasizes into "hardware as a service," sometimes merging with other abusive modes of computing to create a kind of Inkjet Dystopia.
(No word on whether Lime will follow industry leader Bird by sending out bogus legal threats to people who write in detail about its flaws)
The company claims that fewer than 0.0045% of all rides worldwide have been affected, adding that "any injury is one too many." An initial fix reduced the number of incidents, it said, and a final update underway on all scooters will soon be complete.
A software glitch is throwing riders off of Lime scooters [Corinne Purtill/Quartz]