After a month of warnings, it's time for red-light runners to start paying up.Starting this week, drivers in Clearwater and Oldsmar will get $158 traffic tickets if they blow through red lights at six intersections where cameras are watching.The red-light cameras are monitoring two intersections in Clearwater and four in Oldsmar. And there's evidence that they'll be catching plenty of violators.Since June 30, both cities have been issuing warnings to red-light runners caught on camera. In Clearwater, 557 warnings have been mailed to violators photographed at two intersections.That would have been $88,000 worth of tickets. Clearwater would have received less than a third of that money, with most of it going to the state.Oldsmar issued about 500 warnings in the first week alone.Officials in both cities insist, however, that the cameras aren't about revenue — they're about deterring dangerous driving."Whether you agree with them or not, we hope that everyone adheres to the traffic laws for the safety of themselves and others," said Clearwater Mayor George Cretekos, who voted against using the cameras. Two cities are watchingClearwater begins fining violators Tuesday. Cameras will watch the eastbound and westbound lanes of Gulf-to-Bay Boulevard at Belcher Road, as well as the eastbound lanes of Chestnut Street at Fort Harrison Avenue. Those intersections saw the most crashes due to red-light running over the past three years, traffic officials say.Clearwater's City Council voted 3-2 in November to sign a six-month contract with Redflex Traffic Systems. For installing and maintaining the cameras, the Arizona company will earn ticket revenue of $13,000 a month. If red-light violations drop by at least 15 percent in six months, the program will automatically be extended another three years.Oldsmar begins fining violators Wednesday. Three of the four Oldsmar intersections being watched by cameras are on Tampa Road. Cameras were installed where the road intersects with State Road 580, Forest Lakes Boulevard and St. Petersburg Drive E."Tampa Road is a very busy street, and we've had lots of accidents there," said Lisa Rhea, Oldsmar's public works director. "All of the intersections were chosen because of safety considerations." She added that city revenue from the cameras will be steered to safety or transportation needs.Oldsmar's City Council voted 4-1 last December to approve a five-year contract with American Traffic Solutions to install and maintain the devices.By using red-light cameras, these two North Pinellas cities follow on the heels of St. Petersburg, Tampa, Hillsborough County, Temple Terrace, Port Richey, Kenneth City, Gulfport and South Pasadena.How it worksA 2009 state law allows cities to install cameras at intersections and fine the registered owner of any vehicle caught on camera running a red light.Cameras record the license plates of vehicles moving past a red-light sensor and transmit the footage to a city reviewer.After weeding out false violations — the cameras can capture red-light right turns, which won't merit a ticket — the reviewer sends the footage to the camera company to mail out tickets.Fines start at $158, with $106 tacked on if the payment is late. No points are assessed, and appeals can go to traffic court.Where does that $158 go? For tickets on city and county roads, the state Department of Revenue gets $70, the state Department of Health gets $10, the brain and spinal cord injury trust fund gets $3 and the locality gets $75. For tickets on state roads, the state gets $100, the locality $45 and the trust funds $10 and $3, respectively.Mike Brassfield can be reached at [email protected] or (727) 445-4151. To write a letter to the editor, go to tampabay.com/letters.