Wrapping up our week of The Fifth Element police interfaces…

When the police chase Korben into the permanent fog bank at street level of the city, the exciting car chase must stop. They must slow down and undergo a careful search. The front of the car has an LED scrolling sign between its beacon lights that cuts back and forth between displaying “SLOW” and “POLICE.”

From a citizen standpoint, having such text can certainly make the police’s circumstances and desires quite clear. Then again, language can be quite ambiguous. What would you do if you saw a police car that read, “CELLAR DOOR” as it passed? How are you meant to comply?

Though we never actually see the sign change to display any other text, the fact that it’s LED implies that it can and does. Sure, I get the movie’s joke of the police calling themselves “slow,” but there are lots of interaction questions left unanswered. Can the officers in the car change the sign? If so, how? Does the passenger have a keyboard? Or is it voice command? If there’s a control available to the driver, how is it made safe, and not as deadly as a driver trying to compose a text message today? And to what degree can the message be changed? Can they create anything, or do they select from a commissioner-approved menu of options? Or can they not control it at all—is the sign completely controlled from dispatch, or from some context-aware algorithm?

The film gives no clues, so it’s left as an exercise for the design viewer. Which, sometimes, is just the way I like it.