Portland is a serious bicycling community. But not so serious that it can't have some fun with its bike lanes. Some wag painted a whole bunch of Mario Kart items along a stretch of North Williams Avenue in the city.

The symbols include speed boost arrows, bananas, mushrooms, and stars. So far nothing exotic or offense-based, like the shells. They're there to provide a little humor and inspiration to cyclists commuting home.

Writes one biker on a Portland bike blog:

As I pedal home from work, though, I find it engaging and humorous. Would motorists similarly decorate their lanes? I suspect not - this good-natured vandalism is a sign that bikers take pride in their bike lanes and the biking community we've created.

No one's claimed responsibility and there's no word from the city about removing them.

A Bike Lane Video Game On N. Williams [BikePortland.org; video by KATU-TV, Portland. Thanks Alvaro. G!]