As daylight hours decrease, the Indiana Department of Transportation reminds drivers to stay alert for road crews. One way INDOT continues to increase awareness of workers in low-light or low visibility conditions is through Project Greenlight, a program to equip highway workers with Guardian Angel safety lights.
“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.”
Guardian Angel lights are wearable devices with flashing green patterns that increase worker visibility from all directions. When worn with a high visibility vest, these lights help workers become 89% more visible to the traveling public according to a study from Battelle Memorial Institute.
The human eye is most sensitive to green light, seeing the color green 300% more than others and making it the most visible from longer distances. These lights also help identify humans in work zone because they are easily distinguishable from other standard work zone lighting, which is typically white or amber.
Studies show drivers are more likely to move over and slow down when they see these green lights in work zones. INDOT began piloting Project Greenlight in fall 2025, with approximately 1,100 units now distributed to workers throughout the state. INDOT Highway Technicians and Hoosier Helpers are encouraged to use the green lights during overnight operations, as well as times when visibility might be lower including weather conditions like fog, rain or snow.
Green safety lights were brought to INDOT through its Innovation and Process Improvement Division. Innovation is one of INDOT’s core values as the agency looks to challenge the status quo through creative thinking and new technologies. An annual competition is held for INDOT employees to submit innovative ideas that make jobs safer, more efficient and more effective. Those ideas are then vetted and voted on internally and implemented throughout the agency.
