BLs just look like shoulders. Many cyclists even have trouble telling them apart.
If you want to attempt to communicate that cyclists may be around to motorist I think large yellow 'Bicycle' signs on the road side would have a better effect. Signs like this can even be better as they don't communicate where (which is usually with BLs: out of the way, out of concern) the cyclist may be.
I'd like to know what unique benefit bike lane stripes provide over other facilities (wide lane, shoulder, signage)
Al