UDOT

Engineers are studying visibility of lanes,while improving safety and saving tax payer dollars 

The Utah Department of Transportation is using mobile retroreflective technology to assess the visibility of lane markings on Interstate 15. Instead of relying on crews standing on the highway measuring lane marking visibility, this new technology allows UDOT to do it solely using moving vehicles equipped with new technology. 

This allows UDOT to more comprehensively assess the visibility of its lane markings in any weather condition, and determine how to address visibility problems, while also saving taxpayer dollars and making the data collection process safer for highway travelers and crews. 

UDOT crews are collecting data this week along southbound I-15 in Salt Lake and Utah counties. 

Retroreflectivity is enabled by adding special glass beads or microprisms to an object. UDOT embeds these materials into its lane markings to increase their visibility, as retroreflective materials can bounce light back in one direction instead of scattering it, like typical reflective items. 

While UDOT has been testing different kinds of lane markings for the past five years, it has recently improved its collection method with mobile retroreflective technology. 

Previous measurements required crews to slowly pace over lane markings on a highway, holding a retroreflectometer as it scanned lane markings with lasers and collected data. This method not only took more time, but increased inconvenience and risk for anyone on the road, as crews had to create work zones in high speed, high volume areas, like lanes or on-ramps. 

Now, UDOT is deploying a moving data collection method, which uses mobile retroreflectometer units (MRUs) to safely and efficiently collect data on lane marking visibility. Once the MRU is mounted to a car, it follows behind another car, which splashes water on the lane striping, and assesses the visibility of lane markings when wet. 

“Any time we can do our jobs safely, and get the data we need without anyone getting hurt and impacting the public, it’s a big win,” said Abdul Wakil, UDOT maintenance asset engineer. “Not only are we helping to keep routes safe and efficient in the present, but we’re also looking for innovative ways to improve their travel experience in the future — while keeping our crews safe.”

MRUs also decrease the costs associated with testing retroreflectivity, as the previous method required the Utah Highway Patrol and UDOT’s Incident Management Team (IMT) to create buffers and watch the workzone as crews gathered data with the static retroreflectometers. Now, crews are able to collect data while remaining in motion, without the assistance of UHP or our IMT following behind and creating a buffer from traffic—saving time and money in resources. 

“After Governor Cox emphasized the need for increased lane visibility, we’ve been looking for new ways to contribute to that goal,” Wakil said. “This technology is helping us to assess striping condition data and take steps in the right direction to improve the safety of all drivers on Utah roads, no matter the weather conditions.”

UDOT has five designated testing zones along southbound I-15 between South Salt Lake and Draper. Data is currently being used to inform the installation of wet-reflective tape — which increases visibility in rainy conditions — and is being reported back to companies and partners, which are using the information to improve their products used on state roads.