These police check points spring up all the time in Thailand, and traffic is frequently slowed by chicanes, ropes laid across the ground, sometimes a lift gate which is raised on arrival, sometimes its just left wide open.  
Its been some time since I plotted this, and the mechanism of calming may not be up to date, so I believe a simple yes tag is correct.  When on duty, the Police do find ways to slow you down, and I believe the tag adds to the detail of the node.