Netherlands uses salt on roads to protect asphalt from extreme heat

In the Netherlands, municipalities are increasingly using salt on roads during extreme heatwaves to protect asphalt. While salt is typically associated with winter ice management, it is being used in summer to combat high surface temperatures that can reach 50 to 60 degrees Celsius.

Extreme heat causes asphalt to soften, making it susceptible to deformations, ruts, and increased stickiness as bitumen rises to the surface. This is particularly problematic at intersections and roundabouts where vehicle braking and acceleration are frequent. Salt helps by attracting moisture from the air and the road surface, a process that lowers the asphalt temperature and reduces stickiness.

In Maastricht, salt has been applied to new asphalt to prevent excessive softening. However, this practice is not standardized nationwide. Rijkswaterstaat, the Dutch national road administration, noted that salt is not used on motorways because much of the network utilizes porous asphalt, which is less sensitive to high temperatures. Drivers are advised to maintain steady speeds and avoid sudden braking on visibly dark or deformed road sections.