How Do They Do That? The Unseen Science of Road Linemarking

Is the paint a special road marking blend?

Lana: Absolutely. Over the years, it has evolved from what would be considered a highly non-environmentally solvent based blend of roadmarking paint to today's waterborne-based paints. These are blended to be long-lasting and far safer to handle.

Some people will remember double-yellow lines, which not only required separate storage but were made with harmful chemicals to achieve the bright colour. The shift to white for all major markings was as much about using cleaner paint additives as it was about practical application.

You've spoken about waterborne linemarking, but is there another painting process?

Lana: Yes, it's a thermoplastic material. It's heated to a high temperature until it becomes a liquid, applied like paint, and then sets rock hard. It's thicker and is mostly used in city areas with high traffic flow. It's a longer lasting alternative to waterborne linemarking paint.

It's common at intersections, traffic lights, and roundabouts, mostly in 60-kilometre zones.

How long should a line-marked road last before re-applying the paint?

Lana: The short answer is up to three years. However, it completely depends on the environment. Dusty, dirty, drought or flooded road conditions affect the lines and the roads themselves.

The amount and type of traffic also play a huge role. The more wheels that pass over, plus wet years versus dry periods, means different life cycles for road maintenance.

We work on some roads that are repainted every 12 months to two years, depending on the council or roads authority and their specific maintenance program.