Iowa DOT Testing New Pavement Marking Systemeditor@aashto.org July 31, 2020 0 COMMENTS
The Iowa Department of Transportation explained in a recent blog post that slow-moving maintenance activities, such as painting pavement markings, is some of the most dangerous work conducted by its highway crews.
[Above photo by Iowa DOT.]
That’s why the agency is testing a new roadway marking system this summer – an epoxy-based paint system that applies paint into pavement grooves versus the current process of applying a layer of water-borne paint that includes tiny glass beads for boosting nighttime marking visibility.
“Because this is Iowa and our harsh weather conditions require snow-removal equipment that can scrape off the paint and glass beads, many of our roads, and especially our interstate markings, need to be repainted every year,” explained John Hart, an Iowa DOT engineer heading up the epoxy painting project. “The nature of the work means we have to paint the lane markings while traffic is speeding by, increasing the danger for both travelers and our crews.”
He said that because the epoxy painting process requires grooves to be cut into the pavement, it is more cost-effective and safer to do paint markings while road segments are under construction and not open to traffic.
In addition to applying the paint into a groove, which will help it stay on the road longer, the new system uses a process where chemicals are mixed together and harden like an epoxy. Glass beads are also dropped into the surface of the paint before it hardens to produce a pavement marking with a very durable finish, Hart noted.
“From our research, we’re expecting the new pavement markings to last four years,” he added. “Not having crews painting the interstate lines every year will be a significant safety improvement. Because the groove is about two times deeper than the layer of paint, we expect to be able to apply new paint two times before the groove will need to be cleaned out or a new groove cut into the pavement.”