Here we have a classic S-curve in the midst of a town that borders on Lake Geneva. The town is located on the hills that rise from the lake, and the curvature of the street probably derives from the topography - the easiest means to obtain a constant grade on a street that climbs a hill is to have it cross contour lines at constant intervals - this produces a continuous grade with little or no need for excavation and fill. A continuous rate of climb is desirable because it minimizes the maximum grade. (If the grades are slight, it is less important that they be continuous.)
Most European towns were laid out when the movement of earth was still accomplished entirely by muscle power, so there was a great economy in holding the volume to be moved to a minimum. Hence we have streets that climb at a steady angle by following the contours of the land.
All of this has led to a classic, beautiful reverse curve. The street is wide enough, and the curvature gentle enough, that we can see both the initial curve and the reverse curve in the middle distance.
Notice that the line of the buildings has not slavishly followed the edge of the street, which leads to an interesting open area nestled in the corner between two buildings..
The name implies that this is one of the most important streets in town, yet it is still quite narrow.
City Design Home