A clear path home: IDOT’s roadway marks bring ‘good news’ for motorists

Driving at night is one thing. Driving in the dark when it’s raining cats and dogs is another. Once you lose the ability to see the centerline markings, it can get downright dangerous.

Vehicles pass by all-weather markings along I-80 near Princeton, Illinois earlier in September 2018.

Illinois Department of Transportation takes those risks seriously, and it’s something they’re partnering with Illinois Center for Transportation to improve.

“The need for providing guidance when the road conditions are less than ideal, (such as) rain, sleet or snow, is critical for the safety of our drivers,” said Kelly Morse, IDOT chief chemist and technical review panel chair for the joint research project.

Neal Hawkins, associate director of Iowa State University’s Transportation Research Center, who serves as ICT and IDOT’s project investigator for the joint research project — “R27-120: Evaluating All-Weather Markings and Lab Methods to Simulate Field Exposure,” was up for the task to improve centerline markings visibility in adverse conditions.

For researchers, it all boiled down to two questions: Can these all-weather pavement markings provide wet night condition visibility, and how durable are they over time?

Their quest to answer such difficult questions began with testing all-weather markings against Illinois roadways during Mother Nature’s continuous-wetting seasons — winter and spring.

Researchers tested all-weather marking material, such as epoxy, polyuria, tape, thermoplastic and urethane, on Illinois roadways, including I-55, I-57, I-80 and I-355.

Tape ultimately proved to be the best adherent and in 2016, Hawkins tested two vendors’ tapes along I-80 and U.S. Route 3 — near Princeton and Waterloo, Illinois, respectively.

Contractors installed the tapes on new asphalt surfaces within a recessed groove on I-80. U.S. Route 3’s tapes, however, were in-laid, a process in which the asphalt-finishing machine rolls the tape into the new driving surface.

In order to monitor the all-weather markings’ progress, Hawkins measured the adherent’s retroreflectivity, an object’s ability to reflect light, one month after application and again after each of the three winter seasons.

The results?

Hawkins noted that the tapes provide “superior performance when tested under wet conditions” compared to that of the previously used all-weather marking material.

“This is great news for all drivers — young, old, professional drivers, etc.” Hawkins said.

Morse couldn’t agree more.

“The results of this study should help us improve our (IDOT’s) pavement marking practices and policies, and the overall safety of our motorists,” she said.

The recommendation makes great strides for motorist visibility and safety, as it will likely reduce the number of vehicle crashes in wet night conditions where all-weather markings are applied.

Check out volumes 1 and 2 of the project.

Posted July 1, 2019

Written by Emily Jankauski