INDOT illuminates work zones with green safety lights as days grow shorter

Project Greenlight equips 1,100 highway workers with wearable devices that make them up to 89% more visible to drivers.

As daylight hours shrink heading into late fall and winter, the Indiana Department of Transportation is reminding drivers to stay alert for road crews — and it's backing that warning with a splash of green.

Through an initiative called Project Greenlight, INDOT has distributed approximately 1,100 wearable Guardian Angel safety lights to highway workers across the state. The devices flash in green patterns designed to make crews visible from every direction, even in the low-light and low-visibility conditions that define the season.

"Crews are operating in darker conditions more often as we head into late fall and winter," said INDOT Commissioner Lyndsay Quist. "Having these green lights is a small but meaningful way to help keep them safe. Always slow down and stay alert in work zones, especially if you see green lights that indicate workers are present."

The choice of color is deliberate. The human eye is most sensitive to green light, perceiving it roughly 300% more readily than other colors, which makes it the most visible hue at longer distances. The lights also stand apart from the white and amber lighting typically used in work zones, helping drivers quickly distinguish a person on foot from equipment and traffic-control devices.

Paired with high-visibility vests, the lights make workers up to 89% more visible to passing drivers, according to a study by the Battelle Memorial Institute. Studies also show drivers are more likely to move over and slow down when they spot the green lights in a work zone.

INDOT began piloting Project Greenlight in fall 2025. The lights are now in the hands of Highway Technicians and Hoosier Helpers throughout Indiana, who are encouraged to wear them during overnight operations and any time visibility is reduced — whether from fog, rain, snow, or the early sunsets of the season ahead.

The green safety lights reached INDOT through its Innovation and Process Improvement Division, part of an agency culture that treats innovation as a core value. Each year, INDOT holds an internal competition inviting employees to submit ideas that make jobs safer, more efficient, and more effective. Submissions are vetted and voted on internally, then put into practice across the department.

Project Greenlight is one result: a creative, employee-driven idea now helping protect the men and women who build and maintain Indiana's roads — and the drivers who share them.

As the clocks fall back and darkness arrives earlier, INDOT's message is straightforward: slow down, stay alert, and when you see green lights flashing ahead, know that workers are nearby.