For years the high line railroad overpass - which is actually two overpasses because the rail line crosses U.S. 30 in both directions - has served as a giant community bulletin board.
Everything from birthday wishes to advertising fairs, church bazaars, concerts, book sales and other special events are announced on banners hanging from the overpass all year, sometimes covering both concrete structures.
Paths worn up to the sites and hundreds of fragments of dangling ropes, twine and wire testify to their popularity.
"We figured it was just another way to get the word out," said Brian Kump, assistant director of Chambersburg's recreation department, who advertised discount passes to Chambersburg Municipal Swimming Pool on a banner on the high line for the first time in May.
Usually sticking to the safer side of advertising by placing announcements in newspapers or mailing flyers to residents, Kump said he crawled up the bank through the bushes this year because he thought more people would see it and because "everybody else is doing it."
Whether it's worth the risk to advertise on the high line is questionable, because it's hard to read the signs from a car and hold your position on the road.
But some veteran high line advertisers said they swear by it and try to design their banners to stand out and say as much as possible with the fewest possible words.
"We try to have something colorful to catch the eye and we try to have the date, time, place and some key words," Luka said. "You can't expect much reading time."
Advertisers recommend banners and signs be made of a strong material, such as canvas, that will withstand the elements.
Though residents often call the borough offices asking permission to hang their signs from the high line, borough secretary Tanya Mickey said the borough can't authorize it because the property is owned by Conrail.
Officials from Conrail could not be reached for comment.
To most advertisers, the prime space is considered free and to be placed at your own risk.
There are unwritten rules among advertisers that no one's banner should be covered by another, and that once the event is over the sign should be immediately taken down.
"You have to wait for an open spot. It's not good manners to take someone else's down," Luka said.