Much road traffic between the cities of Franeker and Harlingen originally travelled along the Midlumerweg (now the Midlumerlaan, or Midlumer Avenue). The locks of Van Harinxmakanaal and Tjerk Hiddes had not yet been built. 

Here on the Midlumerweg, the German forces had placed a so-called Rollsperre near the bridge over the Ried Canal. This was a roadblock where the passage was closed with a large round stone that could be rolled into the opening. 

During the liberation, Canadian forces shelled Harlingen with artillery. This barricade was also targetted because it was on the main access road to the city and the occupying forces had almost certainly placed troops there.  Another Rollsperre was also placed on one of the two access roads on the south side of Harlingen, the Westerzeedijk. 

After the war, the barricades were demolished by the Royal Canadian Engineers.