These signs may appear to be positioned just to catch out cyclists, but at least pedestrians won't hit them. More importantly, nobody should cycle down that bike lane. If you are turning left, occupy the full left-hand turn lane to avoid getting clipped at the corner. If you are going straight on, occupy that same lane, but go on straight. The bike lane is for cylists who are tired of life and wish to die on Stokes Croft rather than in a mountain biking adventure that would make for a popular youtube download.
The sign forces people out early, and so keeps them alive.
Looking in the other direction, there's a van outside a building site occupying the northbound lane.
A bit more of an inconvenience.
But not much. Not really, as the roadworks bethind the lorry have already taken the lane away.
Given how further in to town these lanes are alway occupied by parked cars, we really have to question the value of these lanes. If it is for cyclist safety, then a 20 mph speed limit would actually work and allow people doing deliveries, roadworks, parking outside their shop, etc, to get on with it. All the bike lane does is create unrealistic, unsustainable expectations by both cyclists and drivers.