Light rail molding is decorative, that’s for sure but its real purpose is to hide under-cabinet lighting.
Today lighting is getting thinner and thinner and while most wall cabinets have a ¾” recess in the bottom, a light rail is still helpful obscuring the fixture itself. Your goal is not to be blinded by the light while sitting in the next room.
A sidebar here on the location of under cabinet lights: their placement to the front or back of the bottom of the wall cabinet has to do with the type of light fixture. Many of the newer LED fixtures need to be placed closer to the front to get a good cone of light on the countertop. Older style fluorescent fixtures (still available today) are designed to be placed tight to the back wall. Your designer will help in advising you on the proper location for the light of your choice.
Here are some more choices in light rail. One might be perfect for your kitchen.
These two photos show how top and bottom molding can match up for a consistent look. These two molding treatments are mirror images of each other…one as a light rail and one as a top molding treatment.
Any room can benefit by paying attention to the details. Light rail molding is a detail that will pay off in function and good looks.