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Appropriately designed, operated, and maintained signals reduce congestion, improving mobility and air quality. But like all jurisdictions, we struggle to find a way to formalize preventive maintenance while responding to emergency calls and overcoming a ‘fix-it-when-it-breaks' mentality.

After analyzing the operations of the three elements of maintenance—emergency calls, preventive efforts, and shop repairs—we took the plunge and implemented a preventive maintenance plan in fall 2005. By the end of the year, we'd inspected, cleaned, and replaced worn components or 714 traffic signals, 74 intersection beacons, and 300 school flashers on 2,600 miles of road.

One year later, malfunctions — which consume up to an hour from when our control center receives a call to when a technician puts his unit back in service for the next call — had dropped 36%. That translates to 1,786 fewer hours of gridlock.

Malfunctions over the next year were a tad less impressive — down 29% from 2005 — but we attribute that to the 18 new signals that were added to our inventory. (One-third of the signals we maintain are on state routes and permitted by the state.) In 2008 malfunctions were slightly up from 2007, but they were still down 22% compared to the year before we implemented our preventive maintenance plan.

Technicians are identifying loop problems before they become emergency calls. They're replacing bulbs before they burn out. Checking and adjusting height is now on the maintenance checklist, so fewer low-hanging signal heads are being hit by trucks. Rodent bait, ant bait, and wasp spray are standard equipment for formerly infested control cabinets.

While there were some initial costs — mainly, warehousing larger quantities of stock items like controller filters, loop detectors, incandescent bulbs, and modems — there was no increase in labor cost. We handled the additional work by rearranging crews and modifying assignments.

Nor did we need additional vehicles. Because all maintenance is performed in-house, employees use their assigned bucket trucks, loop trucks, and pickup trucks.

As for the plan itself, virtually everything we needed to streamline the process was already in our hands; we just needed to review and standardize procedures.

Because all three maintenance elements are related to each other, we evaluated all three when attempting to standardize preventive maintenance:

Emergency maintenance. We have four technicians on duty from 7 a.m. until 11 p.m. every day, including holidays. Coupled with our in-house responding staff, our extended hours of operation were already providing the county with excellent emergency response.