Usability testing and best practices: Street signs

ARLINGTON, VA – We were inside the beltway to visit a client and had the awkward experience of trying to figure out the meaning behind some street signs related to parking.  The stakes were high because if you did not follow the instructions precisely, then you could risk having your car towed, damaging that car in the towing process, being inconvenienced by the entire odeal, wasting a few hours tracking down and recovering your car, and the stiff parking penalty and towing expense.  So, we wanted to make sure we understood the sign correctly.

When you first look at the sign, it seems unassuming and pretty straight forward.  But look at the sign beneath

This second sign is confusing.  What does it mean?  Can I park or not?  Is today Thursday or not?  Can I park on Thursday or not park on Thursday?  WTF?

My assumption, after deliberation, was that it was okay to park unless it was a Thursday between 1pm-9pm.  And if it was a Thursday between 1pm-9pm, then if I was a market vendor, presumably for some farmer’s market or flea market, then I could park.  Turns out we were correct and did not get towed or a ticket.  But, it is frustrating how unusable, i.e., not user-friendly, not obvious, not intuitive these signs were.  They did not follow the usability principle, “Don’t Make Me Think,” coined by Steve Krug.