ROXBOROUGH - If you drive through a private community in southwest Douglas County, don't be surprised to see someone holding a radar gun on behalf of the Homeowner's Association.

Days later - if you are caught speeding - you may get a letter in the mail saying you owe the HOA money.

Roxborough Park Foundation is now four months in to its speed-enforcement program using a photo radar system.

The HOA started enforcing its own speed rules in November 2012 after multiple complaints of cars speeding through the community.

"Our posted speed limit is 30," Roxborough Park Foundation General Manager Don Yowell said. "And we haven't been unreasonable in its enforcement."

Yowell points to statistics from Nov. 6 to Dec. 5, 2012, published in the Foundation's Echoes newsletter. More than 1,300 cars went above 40 mph in the park. More than 130 vehicles went anywhere from 50 to 80 mph. Four times during daylight hours, Yowell said, someone went above 80 mph.

"I don't want to be a police force, but something has to be done before something terribly bad happens," he said.

Yet, a Roxborough resident named Ligita (who did not want to provide her last name) says the fines she now faces after four letters from the HOA are unreasonable.

"They're a Homeowners Association. They don't have any police powers," she said. "They might be able to prevent me from painting my house purple, but I don't think they have any authority to pass or try to enforce a regulation like this."

Yowell says the association simply wanted to enforce a specific section of its rules and regulations regarding vehicle speeds.

"What good is a rule if you can't enforce it?" Yowell said.

Douglas County Sheriff Spokesman Ron Hanavan says Colorado law limits what traffic violations deputies can cite on Roxborough Park Foundation's roads: Those include DUI, DWAI, improper backing, certain parking violations, and reckless and careless driving.

"We still go back there," Hanavan said. "We do increased patrols."

Since Douglas County is limited in its speed enforcement on private roads, Yowell says the HOA was forced to take action.

"I'd love for it to go to court," he said. "I would challenge a judge to say, 'No, it's not within the association's jurisdiction to do that.'"

9NEWS Legal Analyst Scott Robinson said, "If they follow those rules, and it was passed by whatever majority they needed, then it's probably within their control."

However, Robinson says residents facing fines could challenge the association's rules in court. He also said the rules regarding a resident's responsibility for their guest's speeds may be challenged in court.

"I think the HOA has a responsibility to try and deal with the issue," Jim Donaldson, Ligita's neighbor, said. "I think this is one step in trying to do it."

However, Ligita says she has no plans, as of now, to pay the fines she faces.

"Most of us live up here because we want to be left in peace," she said. "We don't expect to be harassed by our association all the time."