covid road blocks

In London they are putting road blocks on back roads to force trafic onto main roads. They are large heavy wooden planters they dump at the end of the roads with the sign "road closed covid). Now ask yourself how is putting a road block going to protect you from covid???

The way I see it they are getting ready for a mass exodus where people are going to try to escape and they want to block off all the back roads to force people onto the main roads where they will have check points.