Road Markings in Edgewater/W. Rogers Park

Over the last two days, I've seen road markings spray-painted on streets in my neck of the woods (Edgewater and West Rogers Park).  They've been following the bike routes (north on Kenmore, west on Granville, south on Rockwell, west on Bryn Mawr, which is as far as I've followed them).  Anybody know what they're for?