Quite unintentionally, my kids’ Halloween costumes have mirrored improvements to Seattle bike infrastructure over the last few years:
2010: Old style man-in-a-house sharrow (and mail carrier)
2011: Bike box and [winged] bike lane man icon
2012: Neighborhood Greenways
I guess this should have been the year of the bi-directional cycle track, but the kids have decided to come up with their own non-bikey costume concepts.
The nationally-focused Alliance for Biking and Walking have collected other transportation-themed costumes on Facebook. Are you dressed as something bike-related or have you costumed your bike?