A new law that requires highway lighting along Kentucky’s state roadways to be shielded from spilling onto farmland is drawing praise from DarkSky KY, a recently formed chapter of the international organization dedicated to restoring the nighttime environment and protecting communities from the harmful effects of light pollution.
Passed by Kentucky’s legislature earlier this year, House Bill 571 requires the Kentucky Transportation Cabinet to prevent its lights installed on state highways from shining onto agricultural land. New lights the cabinet puts in must be equipped with shielding to prevent harm to crops.
The law – which went into effect July 15 – applies only to outdoor lighting installed and maintained by the Kentucky Transportation Cabinet, not to local streetlights or privately-owned outdoor lighting.
In recent years, researchers have found that artificial light at night can mess with the rate of plants’ photosynthesis, disrupt pollinators' circadian rhythms and even destabilize bacterial networks in soil.
Mayfield Republican Rep. Kim Holloway sponsored the legislation. She said the bill began with a complaint from a Graves County farmer about highway lights shining on his soybeans.
“As I started researching this issue a little bit more, I found that it was a legitimate and growing concern across the state and even throughout the nation, simply due to the expansion of lighting fixtures,” Holloway said. “It's just like what we learned in the fourth grade: [Plants have] got to have a certain amount of daylight [and] a certain amount of darkness in order to be able to photosynthesize correctly. And what happens [when plants are exposed to artificial light at night] is the crops do not mature as they're supposed to, and they essentially are just wasted.”
Though she wasn’t aware of DarkSky KY when she conceived of the bill, Holloway said her research into the effects of artificial light has opened her eyes to the problem.
“The more I read into this,” Holloway said, “I became aware of some other effects of light pollution – just on the health of human beings – and I think that it's certainly an issue worth looking into further.”
DarkSky KY – which was cofounded in 2025 by Kelly Davenport, Aaron Hellems and Dan Price – hailed the new law on social media as a “small but meaningful step for darker skies” and to curb light pollution in Kentucky.
Davenport said the bill recognizes that crops depend on natural cycles of daylight and that artificial light at night can have harmful effects for both plants and farmers.
“I think a lot of people think it's just about safety, but it's more than that. Artificial light at night, it disrupts both our human health and disrupts things with farming, with crops – especially soybeans – and disrupts bird migration and insects,” said the Louisville-based astrophotographer. “The more people know about it, the easier it is to fix it. Light pollution is one of the few environmental problems that we have that can be solved almost immediately.”
According to the law, owners of farmland can file written complaints to the Transportation Cabinet if an existing state highway light spills onto their property. The cabinet is expected to address the problem within 30 days of the complaint.
A statement from a KYTC District 1 spokesperson indicated the agency is evaluating ways to comply with the law while also meeting federal lighting requirements to maintain safety on state roadways.
The statement also said that the Graves County interchange where the farmer who inspired Holloway to author the bill grows some of his crops – at Exit 14 of Interstate 69, near Wingo – could be a particularly pricey one to fix. When the lighting was originally installed, the KYTC spokesperson said it was “purposefully designed to minimize light spill” and already included shields. After HB 571 was passed, the agency added more shielding and reduced the actual number of bulbs in fixtures. The cost and feasibility of additional measures to reduce light spill, the statement also indicated, could run as much as $400,000 at that single location – which represents the cost of completely replacing a pair of high-mast poles with cobra head light fixtures.
“We are continuing to assess mitigation measures to identify a solution that ensures safety, complies with lighting requirements and responsibly stewards limited taxpayer funding,” the statement concluded.
Moving forward, Davenport said the group will strive to create more DarkSky areas in the commonwealth. Currently, only one certified International DarkSky Place calls Kentucky home: Mammoth Cave National Park. The certification – given in 2021 – required the park to evaluate over 700 outdoor light fixtures on its property, retrofit fixtures to make them dark-sky friendly and develop a plan to manage outdoor lighting.
Davenport said DarkSky KY will endeavor to inspire more efforts like this in the Bluegrass State.
“Our goal is to have some of our state parks certified, and then maybe some of our private parks and communities so Kentuckians will have some place they can go out with their families and have educational programs available to them, and also places where they can go out to be awed by the stars, and [where] they can see the Milky Way with the naked eye,” Davenport said.
