Most people would associate a healthy heart with a healthy body. Unfortunately, we know that a healthy heart doesn’t always mean the body is healthy. There are many ailments, both seen and unseen, that can have a significant impact on our overall heath. Much the same can be said about traffic signals. The traffic signal controller—i.e., the heart of the traffic signal—may be state-of-the-art and functioning with a high level of efficiency, yet the “body” of the traffic signal—i.e., the structural components, wiring, etc.—may be in poor condition and suffering from ailments that are not immediately visible.
Over the past several years, we have completed traffic signal condition assessment inspections for several jurisdictions in the Mid-Atlantic region. Like many jurisdictions, the agencies we provided these services to did not have traffic signal condition assessment programs, and were looking for information to support funding for their aging traffic signal infrastructure. Agencies were surprised, and in some cases shocked, at some of the issues that were uncovered. The inspection process included a complete inspection of all the structural components at the intersection: poles and anchor bolts, mast-arms, span wires, traffic signal mounting hardware, hand holes, conduits, and cabinets. Each component was rated on a good-fair-poor scale and ratings for the overall intersection were developed. Major structural components such as poles, mast-arms, and span wires had a larger impact on the overall ratings than other components such as conduits and hand holes.
One of the biggest issues we identified was deterioration around the poles and base plate areas. Several locations were identified that had significant deterioration, including holes at the base of the pole, and “hidden” deterioration. When deterioration was found, a licensed Structural Engineer was brought in to evaluate the safety of the pole and determine if immediate removal was needed. In a handful of cases, the poles did need to be removed. Removal of decorative “shoe box” pole base covers and anchor bolt tightening nut caps frequently exposed significant rusting and deterioration (Figure 1). Since the coverings are not typically removed on a frequent basis, the deterioration goes undetected.
Some pole bases were unable to be fully uncovered, as they were buried under landscaping, brick, grading work at an intersection, or the grade had shifted over time. Removing the brick or earth material to expose the pole base often resulted in the inspection team finding rust and deterioration of the buried areas. Galvanized poles were not immune to this finding, as our inspection teams uncovered numerous galvanized poles that had significant, and unseen, deterioration (Figure 2). Other issues such as significant paint coating failure, vehicle impact damage, and missing pole access covers and rodent barriers were also identified.
Overhead infrastructure such as span wires, signal head mounting hardware, and mast-arms were also inspected. Some of the “overhead” issues that were identified included significant rusting of span wires and hardware (Figure 3), span wire splices, utility violations, trees tangled into spans and service feed lines, missing or loose mast-arm bolts, and mast-arm bolts that were too short and not fully threaded into the mounting plates.
Underground infrastructure such as hand holes and conduits were also inspected. Issues identified included crushed or deteriorated conduits (cables would not “pull”), brick style hand holes that were crumbling, and hand holes that were retaining significant levels of water or sludge (Figure 4).
The information collected during inspection cycles can be used to identify short, intermediate, and long-term maintenance needs, prioritize locations for more significant remedial actions such as traffic signal reconstruction, and justify funding. It also forms the backbone of a complete asset management database with a photographic inventory of each location along with the condition assessment. The jurisdictions have begun to use the information collected to request additional funding for their programs, and to take the necessary remedial actions to further the life of their traffic signal assets. One jurisdiction conducted a follow-up round of inspections approximately five years later, which led to then and now comparisons and some startling findings (Figure 5).
Regardless of a jurisdiction’s size, a traffic signal remedial inspection program should be an integral part of any traffic signal program. Just like our body, a traffic signal needs a periodic check-up and/or complete physical to identify any issues that may impact its overall wellbeing and keep it “healthy” too.
