high congestion, risky driving, or dangerous road conditions, law enforcement may institute so-called "rolling roadblocks," where official vehicles line up across the road and drive at a set speed. Since anyone attempting to pass them would be doing so on the shoulder and thereby garnering a ticket from the officer, traffic speeds are kept at the desired level. Rolling roadblocks have also been used by motorists as a form of protest, for example during the fuel protests in the United Kingdom, or in 2019 by French farmers in tractors. Traffic breaks by vehicles other than automobiles Some traffic breaks have been initiated by vehicles other than automobiles. For example, a motorboat driver initiated a traffic break in the Rivière des Prairies to keep marine traffic away from police operations following a helicopter prison escape from the Saint-Jérôme Detention Facility in 2013. In fiction, Thomas the Tank Engine initiated a traffic break by rapidly shifting between tracks to keep his competitors from winning a hypothetical stunt competition. Furthermore, in the book The No Cussing Club by McKay Hatch, two characters conceive of a scenario whereby a hovercraft in Scandinavia can initiate a traffic break during a police narcotics operation. See also Road traffic control Traffic barrier References Road transport Law enforcement techniques