The products become ineffective due to road dirt, rather than from wear.
In these photos, Wizard Blaster is used to clean white lines on a section of I-5 Freeway. Less than 200' feet of lines were cleaned in this R&D project for Oregon Department of Transportation as we "walked the line". This is dry blasting with the use of a water ring, using water and citric acid solution to "gas off" the soda and enhance the cleaning action.
Our amazing results could not be matched by any other method. Reflectivity of the cleaned lines were 30 points over the minimum requirement and O.D.O.T. was very pleased with the results. There were no chemicals to clean up or dispose of and overall media consumption was minimal.