Probably because if there wasn't a bike lane, bicyclists would be forced to use the road. I'm pretty sure there aren't any bicyclists riding at automobile highway speeds. Obviously counterintuitive to block the bike lane with that sign though.

Some areas in a town near me have bridges that don't have bike lanes, and it's technically illegal for bicyclists or pedestrians to cross those bridges. But there's no other way to get to the other side of town without crossing one or the other bridge.

Act like that'll stop me from crossing on a bicycle if and when I need to? Hell no, but I ain't about to ride in traffic, I ride cautiously in the service lane. That sucks though, the service lanes are lined with reflectors and littered with broken glass and tire fragments and shit.

The world in general needs more proper bike lanes, without boneheads screwing up and making them unsafe with random obstacles.

WATCH FOR BIKES? Well no shit, if that sign is in front of me, I see a bicycle right under my ass, that's what the lane is for right?

Put the stupid sign in the buffer zone and call it a day...