Road markings, such as the double yellow lines in the middle of some streets, are incredibly important for drivers across the country. In Mahwah, New Jersey, though, an additional blue line was painted between those markings in October 2016. However, despite the important meaning behind that move, controversy struck when federal officials got involved.

The double yellow lines found in the center of roads up and down America separate vehicles traveling in opposite directions. Additionally, the markings also indicate that drivers aren’t allowed to pass the car in front of them on that particular stretch of road. But while all vehicle owners should be familiar with the meanings of various road markings, a town in New Jersey introduced something new.

In October 2016 the town painted a thin blue line between the double yellow lines on a stretch of road in Mahwah. Usually, blue markings on the street indicate something very specific, such as parking spots for handicapped drivers. However, this particular gesture had a very different meaning.

It turned out that a local resident had sent a request to Mahwah officials to paint the blue line outside the town’s police station. The marking itself was roughly the length of three football fields, covering a significant stretch of the street. The message behind the blue line, though, was simple.

You see, the Mahwah resident wanted to honor the local police officers, with the blue line representing their appreciation for keeping the town’s community safe. Before long, several other towns in Bergen County, New Jersey, followed suit, adding the blue markings outside their respective police stations. It didn’t stop there, though.

In Dumont, New Jersey, for instance, red lines were painted to thank the local fire department, and green lines appeared for the emergency medical services. However, this seemingly simple gesture kick-started a highly controversial debate. It all stemmed from a letter written in December 2016.