How cyclists are treated when there are road works varies greatly depending on where they are.
I took both of the two photos, spaced in time over a couple of years. The first was taken when I lived in Cambridge and the second since we moved over here to the Netherlands.
In the British example, due to major works on the roads in the North of Cambridge, it is clearly important that two lanes of motorized traffic are allowed to flow. An absolute minimum of space has been taken from the road to provide a shared use bidirectional path of 60 cm in width. With cyclists going in both directions, dog walkers, people pushing prams etc. expected to use this narrow space, there was no room for comfort.
In the Dutch example, near an industrial estate in Groningen, the road works are on the cycle path itself, which is being resurfaced. While is is being done, a whole lane is taken from the road, leaving motorists with one lane to use instead of two, and resulting in a route for cyclists which is still comfortably wide.
I've seen many examples of this kind of thing since we moved, including the closure of a bus lane to make a temporary cycle path and even of a dual carriageway being reduced from four lanes to two in order that the other two lanes can be used by cyclists. I've also seen cyclists excepted from road closures due to works, and temporary bridges built to maintain cycle routes when the main route has been broken by works on the canal.
Cyclists don't disappear when road works are under way, but the habit of cycling can be undone very quickly by making conditions for cyclists unpleasant and it can be very difficult to encourage people back onto their bikes after they've stopped cycling.
You may have seen the first photo before. It was used on the cover of Cambridge Cycling Campaign newsletter 65.