Crews perform preventive maintenance at an intersection in Hernando County. The county received the National Association of Counties 2003 Achievement Award for its program “Applying Best Management Practices with In-House Designed Maintenance Management System.” Photos: Harry Lorick
An ounce of prevention is worth . a pound of cure.
The public works departments in both Reno, Nev., and Hernando County, Fla., have taken this adage to heart by launching traffic signal preventive maintenance (PM) programs.
Proactive maintenance performed on a traffic signal results in a lower life-cycle cost. Thus, as more preventive maintenance tasks are performed, the overall number of problems or failures also decreases.
Each public works department had different traffic signal issues to tackle.
Hernando County—in a semitropical region—maintains 72 traffic signals in a 478-square-mile area with five full-time employees. The county also has experienced rapid population growth—more than 200% since 1980—and is transitioning from a rural to urban area.
Reno—a desert region—maintains 220 traffic signals in a 75-square-mile area with eight full-time traffic employees. Unlike Hernando County, Reno is urbanized and experiencing a considerable, though lower, population growth rate of 34%.Why Now?
Reno and Hernando County had been performing maintenance on a problem-only basis with very few regular maintenance activities scheduled. The goal of the program is not necessarily to replace assets, but to extend their useful life and functionality. The life-cycle of signal components can be easily projected because the life of a traffic signal component is based on the amount of time it's used, with similar daily usage lengths. Components—such as bulbs that need to be replaced—are included as part of this maintenance effort and are determined by the same time-based plan.
Labor can be the most costly component of preventive maintenance. Preventive tasks focus on making sure each signal or other component operates correctly—all the time. By establishing the proper maintenance cycle, an agency can project an adequate inventory of parts and components.
Reno in 1998 and Hernando County in 2001 each established a traffic signal preventive maintenance program after an eight-month evaluation by LAConsulting Inc., Manhattan Beach, Calif. Each had a complete operations review that identified the need for a plan. The Reno review was funded by the Regional Transportation Agency, Washoe County, and the City of Sparks using $54,000 in gas tax revenues. Hernando County's $33,000 review was funded by general funds.
The reviews identified several opportunities for improvement for both agencies, including scheduling work by activity, implementing a maintenance plan for traffic signals, and linking the work to an annual schedule to establish accountability.