You see a road with red reflectors running down the center. What do these red reflectors mean?

Reflectors that show red mean that the roadway is closed to vehicles moving in your direction. In other words, if you continue driving on this roadway, you will be going the wrong way. Therefore, do not enter here. These reflectors will likely show clear, yellow, or white to vehicles moving the right way (i.e., in the opposite direction). [Lane Markings, Chapter 3: Signs, Traffic Lights, and Pavement Markings, Louisiana Class D & E Driver's Guide]