SecretSign: A Method of Finding a Specific Vehicle Privately and Quickly Using Flashing Lights

In this paper we propose SecretSign, an interactive system which enables users of shared-mobility services to find their allocated vehicle quickly without notifying other people of the identity of the target vehicle. A light attached to the target vehicle turns on and off in conjunction with the user’s operation of a remote control device, while the lights on other vehicles blink in ‘random’ patterns created by study participants. We tested a passive approach, in which the light on the controller blinks in conjunction with the target, however we found users could identify the target faster with manual operation. We collected typical user-generated ‘random’ patterns in order to better camouflage the distinct patterns likely to be employed by users. We experimentally evaluated SecretSign in a parking lot, and verified that it is also effective in the daytime. Bystanders were rarely able to identify the user’s vehicle.