Every guide post has white reflectors, occasionally orange ones are also used. There are also blue ones - but what are they good for? Some critics complain that the blue reflectors actually keep wildlife off the road.
These are intended to prevent wildlife from crossing the street in front of an approaching car at night and at dusk. The effect is comparable to CDs being hung in trees to keep birds away - and is said to be particularly effective with game. The shape of the reflectors on the guide posts is also no coincidence: there are two circular reflector on the left side of the road and a reflector in the form of a wide, vertical line on the right side.