We’ve got a date for the third annual Park(ing) Day NYC festivities: September 18. For those unfamiliar with Park(ing) Day, it’s kind of like the Christmas of livable streets. Or maybe Sukkot is a better analogy. Parking spaces all over the city will be converted to mini-parks and pedestrian zones. For a day, the potential to re-program space for cars as space for people feels much more tangible.

Each year the designs get a little more creative, and people in more cities participate. This time around there’s a new wrinkle. Transportation Alternatives is organizing a competition called POP.Park in search of a portable, low-cost, pre-fab design for a Park(ing) spot conversion. These are the rules TA has laid out:

• POP.Parks must fold into a box, reusable bag or tote that one person can carry while
  walking or riding public transportation.
• Building materials that have little impact on the environment are encouraged.
• When assembled, POP.Parks should be no larger than 8’x15′ – the size of a parking spot.
• Materials can be found or purchased, but must not exceed $20 in cost.

The deadline for entries is September 1, with finalists invited to set up their designs on Park(ing) Day. The winner will be selected, American Idol style, through a text message vote. Creative people: Feeling up to the challenge? Here are the details.