On a recent trip to Bar Harbor, Maine, I noticed a small sign placed along many of the area’s hiking trails that simply said: ‘Leave no trace.’ The signs apparently help, as I saw very little litter.

Back here at home, though, I see no such signs—but plenty of litter. I’ve watched people deliberately throw trash on the ground as they walk down the street or get into or out of their car in a parking lot.

Keep America Beautiful, Inc. (KAB) says more than 51 billion pieces of litter hit U.S. roadways each year. It’s an $11.5 billion problem annually, with business picking up the tab for $9.1 billion of that, followed by governments, schools, and other entities.

Trash is also a big environmental problem, particularly when plastic items slip through storm drains into local watersheds and out to sea. KAB spokesman Rob Wallace tells me research reveals that litter on the ground tends to attract more litter. “A littered environment creates a social norm that littering behavior is acceptable and that there is no penalty (either criminal or social) for doing so,” explains Wallace. “Therefore, a littered area is more likely to receive even more litter.”

Rick Siebert, Chief of the Division of Parking Management for Montgomery County, Md., says his jurisdiction discovered a counter-intuitive solution to excessive trash in county parking facilities about 15 years ago: removing all trash cans.

“People would bring garbage bags with them to work and dump them in our trash cans,” says Siebert. “And if the can was full, they’d stack them on top or leave them beside the can, which then drew vermin.”

Siebert says the county now has an outsourced crew go through each garage at least once a day and clean up. “When we took the cans out, litter went down—no more free dumpsters.”

How about you? Do your facilities have trash receptacles? How do you keep parking areas free of litter?

Those little trail signs in Maine make me wonder: Would a ‘leave no trace’ campaign work in a parking lot?