Just off Nimitz Highway, a row of cars line an informal entrance to the viaduct.
Despite signs warning trespassers to keep out, nearby businesses say any type of enforcement is a joke.
"Nobody here is doing anything about it," said John Leary, who owns Island Demo, Inc. in Mapunapuna. "It's sad. We're forgotten down here."
Leary said in the evening there are upwards of 20 vehicles parked near the viaduct. Leary's crews have had to dodge cars weaving through traffic toward the illegal parking lot.
"It's live action. You just got to be careful especially at night," he said.
Outreach workers estimate 200 people live beneath the viaduct. But they say not all of those people who frequent the camp are homeless.
"It's a hot spot for all sorts of activities," said City Councilman Joey Manahan, who claims the viaduct is home to an illegal gambling den.
It's an operation that's gone unchecked for more than a year, he said, adding that he also believes drug dealing and prostitution are happening there.
"I would think the Department of Transportation would enforce their no trespassing laws with regards to those vehicles," Manahan said. "I would think they would be concerned with liability if anything were to happen."
Hawaii News Now asked transportation officials why cars parked on state property weren't being towed. A spokesperson sent us this response after our original story aired.
HDOT, in coordination with the Governor’s Coordinator for Homelessness and the Department of Public Safety, continues the planning necessary to enforce State highways rights of way to keep everyone safe. We have prioritized the areas overlooking the H-1 Freeway and immediately adjacent to Nimitz Highway for trespassing enforcement and cleanup operations and continue to push our resources to this area to maintain them. Enforcement of the no parking restriction at this location without additional outreach, services, and continued trespassing enforcement would not be effective, and would not meet the end goal of connecting people to supportive services. We are currently planning our enforcement efforts for the area under the viaduct, and will address the parking restriction holistically with the enforcement when plans are set, and resources are available to perform the enforcement and provide outreach and supportive services. In the interim, we will continue to address health and safety issues that arise as our resources allow.
Leary, the business owner, said all of the issues in the area has him considering a move.
"I would love to get out of here," he said.
In the meantime, he says everyone should have to abide by the same rules.
"We get a ticket if we're parked on the street more than two days. They don't do anything about those people," he said.