Making his mark
There are many ways to remove painted markings from asphalt, but they are not equally effective.
Changes in street markings are needed from time to time, for example as lane changes and turning restrictions take effect. Removing the obsolete marking material can be challenging; on the one hand it could cause damage to the pavement, and residual "ghost" markings can cause confusion for drivers especially when it's dark or wet.
Civil Engineering student Adarsh Malik investigated this issue for his final year research project. He identified and evaluated a range of pavement marking removal technologies, considering how complete was the line removal, what effect that had on an asphalt pavement surface, and how the costs of each method compared.
Adarsh concluded that grinding is effective where the surface is relatively flat. An alternative is to use a grinder to remove marking material above the surface then water/soda blasting to remove the remainder. Different blasting systems are available depending on the extent of work required. Adarsh recommended using stickers instead of paint for temporary road markings, to reduce the costs of removal and safeguard the pavement. Adarsh consulted with the Dunedin City Council in the course of his investigation. The Council is grateful for his report and is considering the options proposed.
Image credit: Adarsh Malik, used with permission