Switchbacks: Roads That Fold Uphill
A mountain road climbs by refusing to go straight, and from above its turns read like a line drawn by someone who kept changing direction.
Most paved mountain roads are built to keep the gradient somewhere under ten percent, because heavy vehicles struggle above that and brakes overheat on the way down. A slope that rises six hundred metres over a short horizontal distance cannot be met head-on at that angle, so the road lengthens itself instead, running across the face of the hill, turning back, and running across again. The Stelvio Pass in northern Italy does this forty-eight times on its eastern side, and each hairpin is numbered on a small stone marker.
Seen from a ridge or from a drone, the pattern becomes something else. The grey band of the road stacks in loose layers, the turns line up roughly one above another, and the retaining walls on the outside of each bend catch the light differently from the slope around them. In late afternoon the asphalt holds a pale sheen while the grass between the loops drops into shadow, so the whole climb reads as a single ribbon pressed into the mountain. A car on it is a moving point that seems to go nowhere, turning left, then right, then left again, and only slowly rising.
Engineers sometimes count switchbacks as a cost of steep ground, the price paid in length for every metre of height. In a photograph they are closer to handwriting, a record of how a slope was negotiated rather than conquered. On a wide screen such a frame lets the eye make a version of the drive, starting at a bend near the bottom edge and working upward through each fold until it reaches the pass.
