Trouble explained: This is how holes appear in the road surface when temperatures are below zero

Due to the winter weather, drivers experience significant inconvenience. Not only do cars no longer want to start and more accidents occur, but there are also traffic jams due to blocked lanes and sometimes holes appear in the road surface seemingly spontaneously.

How exactly does asphalt damage occur? It must be looked for in the open surface layer that covers 90 percent of our highways. The “very open asphalt concrete” (Zoab) on Dutch highways ensures less traffic noise and increases the capacity of the road by reducing splashing and driving water when it rains. Ideal in almost all weather conditions except freezing cold.

Holes in predominantly older road surfaces

Inge van Vilsteren from Rijkswaterstaat explains: “When the asphalt is a little older, moisture gets between small cracks in the road surface. This is usually not a problem as it stays liquid. When it freezes at night, the water turns to ice. This causes it to expand, creating larger and larger cracks that continue to fill with water over the course of the day. The process is then repeated and after a few days of bitter cold, the stones are pressed out of the porous asphalt. This is how cracks become holes.”

Although there is very open asphalt concrete on more than 90 percent of Dutch highways, damage does not occur everywhere. The spokesman explains: “It mainly affects locations where the road surface is a little older.” We had already planned to replace most of these locations this spring. But now the asphalt is under so much stress that it collapses prematurely.”

Lanes closed, no work

Sometimes lanes are closed and there are traffic jams, but work is not always visible. Rijkswaterstaat explains: “Sometimes the holes in the road surface are so large that they can also cause tire damage.” In such a case, we try to plan emergency repairs as quickly as possible. However, this is not always possible, for example when there is still a lot of traffic rushing past the plows. We then decide to carry out repair work at night.”