I found that for the chronic tailgater that they have gone into brain fade, or they are on the cell phone, so to wake them up and encourage them to go around I just turn on the RH turn signal. They just assume I will be slowing down to get off the highway or I am going to pull on the shoulder.

They usually wake up and go around. Because anyone that tends to do that for a long time has an IQ somewhat lower than room temperature I generally wait until there is no traffic along side of them so they can easily pull around without thinking. Wouldn't want them to hurt themselves.

At 62.4 mph I get to do this a lot.

When I drive with fast Roger it is not necessary.