The Right of way law, also known as the "South Paw" law is designed to keep the left lane open for passing and emergencies and is now being enforced. 

In a news report from Fox 17, The Michigan State Police will be stopping motorists for traveling in the left lane or Holding the left lane, which means that they are not moving into the right hand lane to allow for passing traffic as prescribed by state law.

The report from Fox states,

1st Lt. Chris McIntire from the Rockford MSP Post said in a press release that the main reason for the initiative is to educate drivers who don't know that the left lane is reserved for the passing motorist.  He says that driving slow in the left lane is disruptive to traffic flow and can be dangerous, as frustrated motorists attempt risky moves to get around the offending driver.

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