Practice saves asphalt from melting on Dutch highways The sight of a snowplow spreading salt on a highway in the middle of the summer heat may seem like a…
Practice saves asphalt from melting on Dutch highways
The sight of a snowplow spreading salt on a highway in the middle of the summer heat may seem like a ridiculous technical error, but it is actually a strictly observed road maintenance protocol in the Netherlands. According to information, when air temperatures exceed 40 degrees Celsius, the Dutch infrastructure agency takes these seemingly winter measures to protect the pavement from destruction.
Danger of thermal overload
Telemetry data collected by the Rijkswaterstaat agency shows worrying trends during summer heat waves. On key transport corridors connecting Amsterdam and Haarlem, the temperature of the asphalt itself regularly exceeds 50 degrees. This leads to serious thermal overload in the areas with the most intense traffic.
The most vulnerable areas are roundabouts, motorway access ramps and areas with frequent stop-and-go traffic. At these hotspots, the heavy friction of the tyres literally tears the soft, liquefied bitumen from the road surface. The result is deep ruts and sticky tar stains that stick to the tyres and pose a serious threat to the stability of vehicles at high speeds.
The chemical solution with salt
Although sprinkling water on the pavement seems like the most logical solution, it only provides a short-term effect due to the rapid evaporation. Instead, experts rely on the hygroscopic properties of salt.
The dispersed salt extracts moisture directly from the surrounding air and creates a lasting cooling layer on the road. At the same time, it absorbs excess moisture from the bitumen itself, which significantly reduces the stickiness of the surface. Municipal services often combine salt with finely crushed sand, whose role is to fix the softened bitumen before it can stick to hot car tires.
Illustrative photo: pexels-jan-van-der-wolf-11680885-24827190
