We have a few blocks of protected lanes on a few downtown streets. It just occurred to me they were put in around the time the bike share rental racks appeared all around that area. I haven't seen the lanes get much use and the bike share enterprise has pulled out due to very low usage. The demand is too low to really justify such infrastructure.
By law all new construction and significant reconstruction projects require accommodations for cyclists, but unprotected lanes or sharrows satisfy those requirements.